From: Mark Kantrowitz
Subject: FAQ: Scheme Frequently Asked Questions 1/2 [Monthly posting]
Message-ID: <SCHEME_1_858240016@CS.CMU.EDU>
Archive-name: scheme-faq/part1
Last-Modified: Wed Nov 13 15:17:27 1996 by Mark Kantrowitz
Version: 1.29
Maintainer: Mark Kantrowitz and Barry Margolin <···········>
Size: 56100 bytes, 1156 lines

;;; ****************************************************************
;;; Answers to Frequently Asked Questions about Scheme *************
;;; ****************************************************************
;;; Written by Mark Kantrowitz and Barry Margolin
;;; scheme_1.faq 

This post contains part 1 of the Scheme FAQ.

If you think of questions that are appropriate for this FAQ, or would
like to improve an answer, please send email to us at ···········

Note that the lisp-faq mailing list is for discussion of the content
of the FAQ posting only.  It is not the place to ask questions about Scheme;
use either the ······ mailing list, the comp.lang.scheme
newsgroup or the Scheme Digest (······ for that. If a
question appears frequently in one of those forums, it will get added
to the FAQ list. 

*** Copyright:

Copyright (c) 1993-94 by Mark Kantrowitz and Barry Margolin. 
All rights reserved. 

This FAQ may be freely redistributed in its entirety without
modification provided that this copyright notice is not removed.  It
may not be sold for profit or incorporated in commercial documents
(e.g., published for sale on CD-ROM, floppy disks, books, magazines,
or other print form) without the prior written permission of the
copyright holder.  Permission is expressly granted for this document
to be made available for file transfer from installations offering
unrestricted anonymous file transfer on the Internet.

If this FAQ is reproduced in offline media (e.g., CD-ROM, print form,
etc.), a complimentary copy should be sent to Mark Kantrowitz, School
of Computer Science, Carnegie Mellon University, 5000 Forbes Avenue,
Pittsburgh, PA 15213-3891 USA.

This article is provided AS IS without any express or implied warranty.

*** Topics Covered:

Topics Covered (Part 1):
  [1-0]   What is the purpose of this newsgroup?
  [1-2]   What is the difference between Scheme and Common Lisp?
  [1-3]   Scheme books, introductions, documentation, periodicals,
          journals, and conference proceedings. 
  [1-4]   Where can I learn about implementing Scheme interpreters and 
  [1-7]   Standards for Scheme -- What are R4RS and IEEE P1178?
  [1-8]   How do I do object-oriented programming in Scheme?
  [1-9]   Repositories of Scheme Software
  [1-10]  Publicly Redistributable Scheme Software
  [1-11]  Formatting code in LaTeX (WEB and other literate programming tools)
  [1-12]  Where can I get an implementation of Prolog in Scheme?
  [1-13]  What does SICP, SCOOPS, R4RS, CAR, CDR, ... mean?
  [1-14]  Why is there no EVAL in Scheme?
  [1-15]  World-Wide Web (WWW) Resources
  [1-16]  Why is Scheme called 'Scheme'?

Topics Covered (Part 2):
  [2-1]   Free Scheme implementations.
  [2-2]   Commercial Scheme implementations.
  [2-3]   What Scheme-related discussion groups and mailing lists exist?

Search for \[#\] to get to question number # quickly.

*** Recent Changes:

;;; 1.19:
;;; 20-OCT-94 mk    Added FTP location for Scheme84.
;;;  3-NOV-94 mk    FTP collections on have moved to
;;;  3-NOV-94 mk    Added Christian Queinnec's Lisp book to [1-4].
;;; 1.20:
;;; 15-NOV-94 mk    Updated location of Ken Dickey article.
;;; 1.21:
;;; 22-NOV-94 mk    Scheme Repository at Indiana University WWW page.
;;;  7-DEC-94 mk    Updated EdScheme entry in [2-2].
;;; 1.22:
;;; 16-JAN-95 mk    Updated Schemers entry. 
;;; 31-JAN-95 mk    Added Manis' book to [1-3].
;;; 1.23:
;;; 13-MAR-95 mk    Updated EdScheme and 3DScheme for Windows in part 2.
;;;  7-APR-95 mk    Added Scsh entry provided by Olin Shivers to [2-1].
;;; 1.24:
;;; 14-APR-95 mk    Updated description of the Schemer's Guide.
;;; 1.25:
;;; 13-JUL-95 mk    Updated 3d-Scheme entry in part 2.
;;; 1.26:
;;; 17-AUG-95 mk    Updated ELK entry in part 2.
;;; 11-SEP-95 mk    Updated EdScheme and 3DScheme for Windows entries in part
;;;                 2.
;;; 19-FEB-96 mk    Updated Schemer's entry in part 2.
;;; 19-MAR-96 mk    Added entry on comp.lang.scheme.scsh to part 2.
;;; 13-NOV-96 mk    Added entry for MzScheme.

*** Introduction:

Certain questions and topics come up frequently in the various network
discussion groups devoted to and related to Scheme.  This file/article is
an attempt to gather these questions and their answers into a convenient
reference for Scheme programmers.  It (or a reference to it) is posted
periodically.  The hope is that this will cut down on the user time and
network bandwidth used to post, read and respond to the same questions
over and over, as well as providing education by answering questions
some readers may not even have thought to ask.

This is not a Scheme tutorial, nor is it an exhaustive list of all Scheme
intricacies.  Scheme is a very powerful and expressive language, but with
that power comes many complexities.  This list attempts to address the
ones that average Scheme programmers are likely to encounter.  If you are
new to Scheme, see the answer to the question "How can I learn
Scheme?" [1-3].

The latest version of this file is available via anonymous FTP from CMU: 

   To obtain the files from CMU, connect by anonymous FTP to  []
   using username "anonymous" and password ·····@host" (substitute your
   email address) or via AFS in the Andrew File System directory
   and get the files scheme_1.faq and scheme_2.faq.

You can also obtain a copy of the FAQ by sending a message to
········ with 
   Send Scheme FAQ
in the message body.

An automatically generated HTML version of the Scheme FAQ is accessible by
WWW as part of the AI-related FAQs Mosaic page. The URL for this
resource is
The direct URL for the Lisp FAQ is

We've tried to minimize the overlap with the FAQ postings to the
comp.lang.lisp, comp.lang.clos and newsgroups, so if you don't
find what you're looking for here, we suggest you try the FAQs for
those newsgroups. These FAQs should be available by anonymous ftp from []
in the lisp-faq/, ai-faq/ and scheme-faq/ subdirectories or by email.
For instructions on email retrieval, send a mail message to
··········· with "help" and "index" on separate lines in
the body of the message.

If you need to cite the FAQ for some reason, use the following format:
   Mark Kantrowitz and Barry Margolin, "Answers to Frequently Asked
   Questions about Scheme", comp.lang.scheme, <month>, <year>,, 

Subject: [1-0] What is the purpose of this newsgroup?

The newsgroup comp.lang.scheme exists for general discussion of
topics related to the programming language Scheme. For example, possible
topics can include (but are not necessarily limited to):
   announcements of Scheme books and products
   discussion of programs and utilities written in Scheme
   discussion of portability issues
   questions about possible bugs in Scheme implementations
   problems porting an implementation to some architecture
Postings should be of general interest to the Scheme community. See also
question [2-3].

The comp.lang.scheme newsgroup is archived in
on a weekly basis.

Questions about Common Lisp should be directed to the newsgroup
comp.lang.lisp.  Discussion of object oriented programming in Lisp to
the newsgroup comp.lang.clos. Discussion of functional programming
language issues in general should be directed to the newsgroup
comp.lang.functional.  Discussion of AI programs implemented in Scheme
should sometimes be cross-posted to the newsgroup

Subject: [1-2] What is the difference between Scheme and Common Lisp?

Scheme is a dialect of Lisp that stresses conceptual elegance and
simplicity. It is specified in R4RS and IEEE standard P1178. (See
question [1-7] for details on standards for Scheme.) Scheme is much
smaller than Common Lisp; the specification is about 50 pages,
compared to Common Lisp's 1300 page draft standard. (See the Lisp FAQ
for details on standards for Common Lisp.) Advocates of Scheme often
find it amusing that the entire Scheme standard is shorter than the
index to Guy Steele's "Common Lisp: the Language, 2nd Edition".

Scheme is often used in computer science curricula and programming
language research, due to its ability to represent many programming
abstractions with its simple primitives. Common Lisp is often used for
real world programming because of its large library of utility
functions, a standard object-oriented programming facility (CLOS), and
a sophisticated condition handling system.

See question [1-8] for information about object-oriented programming
in Scheme. 

In Common Lisp, a simple program would look something like the

   (defun fact (n)
     (if (< n 2)
         (* n (fact (1- n)))))

In Scheme, the equivalent program would like like this:

   (define fact
     (lambda (n)
       (if (< n 2)
         (* n (fact (- n 1))))))

Experienced Lisp programmers might write this program as follows in order
to allow it to run in constant space:

   (defun fact (n)
     (labels ((tail-recursive-fact (counter accumulator)
                (if (> counter n)
                    (tail-recursive-fact (1+ counter)
                                         (* counter accumulator)))))
       (tail-recursive-fact 1 1)))

Whereas in Scheme the same computation could be written as follows:

   (define fact
     (lambda (n)
       (letrec ((tail-recursive-fact
                 (lambda (counter accumulator)
                   (if (> counter n)
                     (tail-recursive-fact (+ counter 1)
                                          (* counter accumulator))))))
               (tail-recursive-fact 1 1))))

or perhaps (using IEEE named LETs):

   (define fact
     (lambda (n)
       (let loop ((counter n)
                  (accumulator 1))
            (if (< counter 2)
              (loop (- counter 1)
                    (* accumulator counter))))))

Some Schemes allow one to use the syntax (define (fact n) ...) instead
of (define fact (lambda (n) ...)).

Subject: [1-3] Scheme books, introductions, documentation, periodicals, 
               journals, and conference proceedings.

Introductions to Scheme:

   The following four books from MIT Press are listed in order of
   increasing difficulty. The first is good for the complete novice,
   the second for students with little or no previous exposure to programming,
   and the third and fourth for more advanced students. The third and
   fourth may also be used to learn a variety of powerful programming
   language concepts. One of these books will suit your needs.

   1. Daniel P. Friedman and M. Felleisen.
      "The Little LISPer"
      MIT Press (Cambridge, MA), 3rd printing, 1989. ISBN 0-262-56038-0.
      Science Research Associates (Chicago), 3rd ed, 1989. 206 pages.

      Good for a quick introduction. Uses Scheme instead of Common Lisp.
      (The book uses a dialect of Scheme with footnotes about translating to
      Scheme or Common Lisp. The footnotes won't allow a non-expert to use
      Common Lisp for the advanced chapters because of the complexity.)

   2. Brian Harvey and Matthew Wright
      "Simply Scheme: Introducing Computer Science"
      MIT Press, Cambridge, MA, 1994. 583 pages. 
      ISBN 0-262-08226-8. $49.95.

      This book is ideal for students with little or no previous exposure to
      programming. The book is designed to be used before SICP (the authors
      call it a SICP "prequel"), and makes Scheme fun by sheltering the
      students from potentially confusing technical details. Unlike Pascal
      or C, the emphasis is on ideas, not obscure matters of syntax and
      arbitrary rules of style.  High schools who have shied away from using
      Scheme because they found SICP to be too challenging should consider
      using this book instead.

      The text gradually and gently introduces students to some of the key
      concepts of programming in Scheme. It starts off with functions and
      function composition and continues with the notion of functions as
      data (first-class functions) and programs that write programs
      (higher-order functions).  Since the complexity of the language is
      hidden, students can get involved in some of the more interesting and
      fun aspects of the language earlier than in other texts.  Then the
      book progresses through the more complicated concepts of lambda,
      recursion, data abstraction and procedural abstraction, and concludes
      with sequential techniques, but with careful attention to topics
      students often find difficult.  There are five chapters on recursion
      alone! There's also a pitfalls section at the end of most chapters to
      help students recognize and avoid common errors.

      The book uses several programs as examples, including a tic-tac-toe
      program, a pattern matcher, a miniature spreadsheet, and a simple
      database program.  Source code for the programs is available by
      anonymous ftp from, or for $10 on
      IBM or Macintosh diskettes from the publisher.

   3. Harold Abelson and Gerald Jay Sussman, with Julie Sussman.
      "Structure and Interpretation of Computer Programs"
      MIT Press (Cambridge, MA) and McGraw-Hill (New York), 1985.
      542 pages. ISBN 0-262-01077-1, $55. The teacher's manual, which is
      also available from MIT Press (ISBN 0-262-51046-4 $20), does NOT
      contain solutions to the exercises, but does contain hints on
      teaching with the book. 

      Starts off introductory, but rapidly gets into powerful
      Lisp-particular constructs, such as using closures,
      building interpreters, compilers and object-oriented systems.  Often
      referred to by its acronym, SICP, which is pronounced "Sick-Pee". This
      is the classical text for teaching program design using Scheme,
      and everybody should read it at least once. MIT problem sets are
      available from the repositories, and materials from Gustavus
      Adolphus College are available from 

   4. George Springer and Daniel P. Friedman
      "Scheme and the Art of Programming" 
      MIT Press and McGraw Hill, 1990, 596 pages.
      ISBN 0-262-19288-8, $50.

      Introduces basic concepts of programming in Scheme. Also deals with
      object oriented programming, co-routining, continuations.  Gives
      numerous examples. Has more of an emphasis on teaching Scheme than
      SICP, and can be seen as an alternative to SICP.  Source code from the
      chapters is available from 

   5. Iain Ferguson, Edward Martin and Burt Kaufman.  
      Foreword by Daniel Friedman.
      "The Schemer's Guide: Second Edition"
      Schemers Inc., Ft. Lauderdale, FL, 1995. (see EdScheme entry in [2-2])
      330 pages, ISBN 0-9628745-2-3, $35.95.

      This book assumes no previous programming experience and is ideal 
      for high school or college students.  The book presents
      the elements of modern computer programming in an easy-to-follow and
      entertaining manner.  It gently introduces students to the Scheme
      programming language, guiding them through such concepts as
      functional programming, recursion, data structures, higher order
      functions, delayed evaluation, and object-oriented programming.  The
      text concludes with a significant game-playing project
      involving artificial intelligence. The book strikes a good balance
      between theory and practice, while nurturing good programming
      practices.  The Schemer's Guide has a proven track record of several
      years use in teaching the art of Scheme programming to high school
      students and college undergraduates. A comprehensive teacher's guide
      and an additional set of resource materials including worksheets,
      quizzes, projects, and exams are available to instructors using this
      text. (A Spanish translation will be available by August 1995.)

Older Introductions to Scheme:

   1. Smith, Jerry D.
      "Introduction to Scheme"
       Prentice Hall (Englewood Cliffs, NJ), 1988, 324 pages.
           Focuses on PC Scheme.

   2. Michael Eisenberg 
      "Programming in Scheme"
      Scientific Press (Redwood City, CA), 1988. 304 pages.

   3. Two articles in BYTE Magazine, February 1988, by Abelson and
      Sussman, and Clinger.

Online Introductions to Scheme:

   1. The Ken Dickey article, "The Scheme Programming Language", in
      COMPUTER LANGUAGES magazine, June 1992, is available from the
      Scheme Repository at 

      The Revised^4 Report on the Algorithmic Language Scheme is also 
      available from the Scheme Repository.

   2. The Info files from the MIT Scheme implementation.

   3. "Introductory Scheme" by Joseph W. Lavinus and James D. Arthur,
       <·······>. Available from the Lisp Utilities
       Repository as 
       as scmintro.tgz.

Scheme and Artificial Intelligence:

   1. Wolfgang Kreutzer and Bruce McKenzie
      "Programming for Artificial Intelligence: 
       Methods, Tools and Applications"
      Addison-Wesley (Reading, MA), 1990. 682 pages. 
      ISBN 0-201-41621-2.
           Discusses Scheme, Prolog, and Smalltalk, gives an overview of
           the history and philosophy of AI, surveys three major
           programming paradigms (procedural, declarative, and
           object-oriented), and metaphors to AI programming.
           Source code from the chapters is available from 
           as aibook.tar.Z. Some of the programs will only run under MacScheme.

Scheme-based Computer Science Texts:

   1. Vincent Manis and James Little
      "The Schematics of Computation"
      Prentice-Hall, Inc., 1995. 848 pages
      ISBN 0-13-834284-9 (North America), $41
      ISBN 0-13-433772-7 (International).

      For a copy of the publication announcement, see 

General Scheme reference books include:

   1. K. Dybvig
      "The Scheme programming language"
      Prentice Hall, 1987.
         Good reference for Scheme.

Scheme-related periodicals include:
   1. LISP Pointers.
      Published by ACM SIGPLAN six times a year. Volume 1, Number 1
      was April-May 1987. 
      Subscriptions: ACM Members $12; ACM Student Members $7; Non-ACM
      members $25. Mail checks payable to the ACM to ACM Inc., PO Box
      12115, Church Street Station, New York, NY 10249.

   2. LISP and Symbolic Computation, Kluwer Academic Press. Volume 1
      was published in 1989. (··· is the editor).  ISSN 0892-4635.
      Subscriptions: Institutions $169; Individuals $80. Add $8 for
      air mail. Kluwer Academic Publishers, PO Box 322, 3300 AH Dordrecht, 
      The Netherlands, or Kluwer Academic Publishers, PO Box 358, Accord
      Station, Hingham, MA 02018-0358. 

   3. Proceedings of the biannual ACM Lisp and Functional Programming
      Conference. (First one was in 1980.)

   4. Proceedings of the annual Lisp Users and Vendors Conference.

See also the Scheme Bibliography from the Scheme Repository
( for additional readings.
A large number of technical reports on Scheme are now available in the
text section (

Subject: [1-4] Where can I learn about implementing Scheme interpreters  
               and compilers?

There is no single book that is really comprehensive, so you will have
to combine reading the sources to the various free implementations
(e.g., Gambit [Feeley] and S48 [Rees]) with bits and pieces of tech
reports and various books.

Books about Scheme implementation include:

   1. John Allen
      "Anatomy of Lisp"
      McGraw-Hill, 1978. 446 pages. ISBN 0-07-001115-X

   2. Samuel Kamin
      "Programming Languages, An Interpreter-Based Approach"
      Addison-Wesley, Reading, Mass., 1990. ISBN 0-201-06824-9
           Includes sources to several interpreters for Lisp-like
           languages, and a pointer to sources via anonymous ftp.

   3. Sharam Hekmatpour
      "Lisp: A Portable Implementation"
      Prentice Hall, 1985. ISBN 0-13-537490-X.
           Describes a portable implementation of a small dynamic
           Lisp interpreter (including C source code). 

   4. Peter Henderson
      "Functional Programming: Application and Implementation"
      Prentice-Hall (Englewood Cliffs, NJ), 1980. 355 pages.

   5. Peter M. Kogge
      "The Architecture of Symbolic Computers"
      McGraw-Hill, 1991. ISBN 0-07-035596-7.
           Includes sections on memory management, the SECD and
           Warren Abstract Machines, and overviews of the various
           Lisp Machine architectures.
   6. Daniel P. Friedman, Mitchell Wand, and Christopher T. Haynes
      "Essentials of Programming Languages"
      MIT Press, 1992, 536 pages. ISBN 0-262-06145-7, $55.
           Teaches fundamental concepts of programming language
           design by using small interpreters as examples. Covers
           most of the features of Scheme. Includes a discussion
           of parameter passing techniques, object oriented languages,
           and techniques for transforming interpreters to allow
           their implementation in terms of any low-level language.
           Also discusses scanners, parsers, and the derivation of
           a compiler and virtual machine from an interpreter.
           Source files available by anonymous ftp from 
     ( or from the
           Scheme Repository in 

   7. Peter Lee, editor, "Topics in Advanced Language Implementation",
      The MIT Press, Cambridge, Mass., 1991.
           Articles relevant to the implementation of functional
           programming languages.

   8. Also see the proceedings of the biannual ACM Lisp and Functional
      Programming conferences, the implementation notes for CMU Common Lisp,
      Peter Norvig's book ("Paradigms of AI Programming: Case Studies
      in Common Lisp", Morgan Kaufmann, 1992. 946 pages. ISBN
      1-55860-191-0), and SICP (Abelson & Sussman). 

   9. Christian Queinnec
      "Les Langages Lisp"
      InterEditions (in French), 1994. 500 pages.
      ISBN 2-7296-0549-5, 61-2448-1. (?)

      The book covers Lisp, Scheme and other related dialects,
      their interpretation, semantics and compilation.

      All of the programs described in the book are available by
      anonymous ftp from
      For more information, see the book's URL
      or contact the author at ··················

Technical reports and journal articles about Scheme implementation include:

   Mitchell Wand and Daniel P. Friedman, "Compiling Lambda Expressions
   Using Continuations and Factorizations", Journal of Computer Languages
   3(1978), 241-263.

   Guy Lewis Steele Jr., "Rabbit: A Compiler for Scheme", MIT AI Memo
   474, Massachusetts Institute of Technology, Cambridge, MA, May 1978.

   Guy Lewis Steele Jr., "Compiler Optimization Based on Viewing LAMBDA
   as RENAME + GOTO", in "Artificial Intelligence: An MIT Perspective",
   Patrick Henry Winston and Richard Henry Brown (eds.), MIT Press,
   Cambridge, MA, 1980.

   Jonathan A. Rees and Norman I. Adams, "T: A Dialect of Lisp or,
   LAMBDA: The Ultimate Software Tool", Conference Record of the 1982 ACM
   Symposium on Lisp and Functional Programming, 1982, 114-122.

   R. Kent Dybvig, "C-Scheme", Computer Science Department Technical
   Report #149 (MS Thesis), Indiana University, Bloomington, IA, 1983.

   William Clinger, "The Scheme 311 compiler: An Exercise in Denotational
   Semantics", Conference Record of the 1984 ACM Symposium on Lisp and
   Functional Programming, 1984, 356-364.

   Guillermo J. Rozas, "Liar, an Algol-like Compiler for Scheme", S.B.
   Thesis, Department of Electrical Engineering and Computer Science,
   Massachusetts Institute of Technology, January 1984.

   David H. Bartley and John C. Jensen, "The Implementation of PC
   Scheme", Proceedings of the 1986 ACM Conference on Lisp and Functional
   Programming, 1986, 86-93.

   David Kranz, Richard Kelsey, Jonathan A. Rees, Paul Hudak, James
   Philbin and Norman I. Adams, "Orbit: An Optimizing Compiler for
   Scheme", Proceedings of the SIGPLAN Notices '86 Symposium on Compiler
   Construction, June 1986, 219-233.  Published as SIGPLAN Notices 21(7),
   July 1986.

   Marc Feeley, "Deux Approches a' L'implantation du Language Scheme",
   M.Sc. Thesis, De'partement d'Informatique et de Recherche
   Ope'rationelle, University of Montreal, May 1986.

   R. Kent Dybvig, "Three Implementation Models for Scheme", Department
   of Computer Science Technical Report #87-011 (Ph.D. Dissertation),
   University of North Carolina at Chapel Hill, Chapel Hill, North
   Carolina, April 1987.

   William D. Clinger, Anne H. Hartheimer and Eric M. Ost,
   "Implementation Strategies for Continuations", Conference Record of
   the 1988 ACM Conference on Lisp and Functional Programming, August
   1988, 124-131.

   David Kranz, "Orbit: An Optimizing Compiler for Scheme", Computer
   Science Technical report #632 (Ph.D. Dissertation), Yale University,

   Joel F. Bartlett, "SCHEME->C a Portable Scheme-to-C Compiler",
   Research Report 89/1, Dec. Western Research Laboratory, Palo Alto, CA,
   January 1989.

   Marc Feeley and James S. Miller, "A Parallel Virtual Machine for
   Efficient Scheme Compilation", Proceedings of the 1990 ACM Conference
   on Lisp and Functional Programming, Nice, France, June 1990.

   Chris Hanson, "Efficient Stack Allocation for Tail-Recursive
   Languages", Proceedings of the 1990 ACM Conference on Lisp and
   Functional Programming, Nice, France, June 1990.

   Robert Hieb, R. Kent Dybvig and Carl Bruggeman, "Representing Control
   in the Presence of First-Class Continuations", Proceedings of the
   SIGPLAN Notices '90 Conference on Programming Language Design and
   Implementation, White Plains, New York, June 1990, 66-77.

   Guillermo Rozas, "Taming the Y Operator", Proceedings of the 1992 ACM
   Conference on Lisp and Functional Programming, San Francisco, CA,
   June 1992, 226-234.

   Dan Teodosiu, "HARE: An Optimizing Portable Compiler for Scheme", ACM
   Sigplan Notices 26(1), January 1991.

Subject: [1-7] Standards for Scheme -- What are R4RS and IEEE P1178?

R4RS is the Revised^4 Report on the Algorithmic Language Scheme,
edited by W. Clinger and J. Rees. It appeared in ACM Lisp Pointers IV,
July-September 1991, and also as MIT AI Memo 848b. It serves as a kind
of standard for the language. It can be obtained by anonymous ftp at
the two Scheme Repositories, and
A HTML version is available as

IEEE P1178 is IEEE Standard 1178-1990, "IEEE Standard for the Scheme
Programming Language", published by IEEE in 1991. ISBN 1-55937-125-0.
It is now also an ANSI standard. It may be ordered from IEEE by
calling 1-800-678-IEEE or 908-981-1393 or writing IEEE Service
Center, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331, 
and using order number SH14209 ($28 for IEEE members, $40 others).

Subject: [1-8] How do I do object-oriented programming in Scheme?

Some Scheme implementations (for example, MacScheme, Feel, Oaklisp, XScheme,
and PC-Scheme) include built-in object-oriented extensions.  

BOS (Bryan's Object System) is a very small object system for Scheme.
It is based around generic functions and multiple inheritance.  BOS
provides more or less the same features as Meroon and the Tiny CLOS
base language. Even though it has not been optimised, it should be
quite a bit faster than those because it does not include a MOP.
BOS has been tested under Scheme 48 and SCM, and should run under any
fairly modern Scheme implementation (especially any which runs SLIB)
with little or no change.  It is available by anonymous ftp from
and the CMU AI Repository in
For more information, write to Bryan O'Sullivan <········>.

MEROON is a package written in Scheme to provide the basic facilities
of an object-oriented programming style through three macros:
define-class, define-generic, and define-method. MEROON offers simple
inheritance, reflective metaclasses and simple dispatching generic
functions with support for multimethods. MEROON also offers indexed
fields subsuming Scheme vectors without inheritance restrictions.
Meroon runs in Scheme->C, PC-Scheme, Chez Scheme, Elk, Bigloo, SCM
with SLIB, and MacGambit. MEROON sources and documentation may be
found in the Scheme Repository as*.tar.Z
and also from*.tar.gz []
The file meroonet*.tar.gz is a toy version of meroon. For more
information, contact Christian Queinnec <········>
or <··················>.

SCOOPS (Scheme Object Oriented Programming System) is an object system
for Scheme written by Amitabh Srivastava/Texas Instruments with 
re-writes by Steve Sherin <······>. [Email to this
address bounced 7/7/93.] This package needs first-class environments.
It is available from the Scheme Repository as

Tiny CLOS is a Scheme implementation of a `kernelized' CLOS, with a
metaobject protocol. The implementation is even simpler than the
simple CLOS found in `The Art of the Metaobject Protocol,' weighing in
at around 850 lines of code, including (some) comments and
documentation. Tiny CLOS is available by anonymous ftp from Tiny CLOS runs in MIT Scheme 11.74 and
should run with only minor modifications in other Schemes as well. If
you want to be added to the ···· mailing list
(technical questions and discussion only), send mail to Gregor Kiczales

YASOS (Yet Another Scheme Object System) is fairly functional in style
and uses delegation.  The implementation includes multiple inheritance
and "send to super" and is much smaller than class-based OO systems.
See Ken Dickey, "Scheming with Objects", AI Expert 7(10):24-33,
October 1992. A copy of the article and YASOS code is available from
the Scheme Repository in pub/scheme-repository/txt/swob.txt. YASOS is also
included as part of SLIB. For further information, contact Ken Dickey

Subject: [1-9] Repositories of Scheme Software

There are several repositories of publicly redistributable and
public domain Scheme code. 

CMU AI Repository, Scheme Section:

   The Scheme Section of the CMU Artificial Intelligence Repository
   is accessible by anonymous ftp to []
   through the AFS directory
   or by WWW from the URL
   and includes more than 200 megabytes of sources and other materials
   of interest to Scheme programmers, including all freely
   distributable implementations and many programs.  Unlike the Scheme
   Repository at Indiana University, the entire contents of the CMU AI
   Repository has been keyword indexed to provide convenient browsing
   of the contents.

   The repository has standardized on using 'tar' for producing
   archives of files and 'gzip' for compression.

   To search the keyword index by mail, send a message to:
   with one or more lines containing calls to the keys command, such as:
      keys scheme awk
   in the message body.  Keywords may be regular expressions and are
   compared with the index in a case-insensitive conjunctive fashion.  
   You'll get a response by return mail. Do not include anything else in 
   the Subject line of the message or in the message body.  For help on
   the query mail server, include: 

   A Mosaic interface to the keyword searching program is in the
   works.  We also plan to make the source code (including indexes) to
   this program available, as soon as it is stable.

   Most of the Scheme Section of the AI Repository appears on Prime Time 
   Freeware for AI, Issue 1-1, a mixed-media book/CD-ROM publication. It
   includes two ISO-9660 CD-ROMs bound into a 224 page book and sells
   (list) for US$60 plus applicable sales tax and shipping and handling
   charges. Payable through Visa, Mastercard, postal money orders in US
   funds, and checks in US funds drawn on a US bank. For more
   information write to Prime Time Freeware, 370 Altair Way, Suite 150,
   Sunnyvale, CA  94086  USA, call 408-433-9662, 408-433-0727 (fax),
   or send email to ···

   Contributions of software and other materials are always welcome but
   must be accompanied by an unambiguous copyright statement that grants
   permission for free use, copying, and distribution -- either a
   declaration by the author that the materials are in the public domain,
   that the materials are subject to the GNU General Public License (cite
   version), or that the materials are subject to copyright, but the
   copyright holder grants permission for free use, copying, and
   distribution. (We will tell you if the copying permissions are too
   restrictive for us to include the materials in the repository.)
   Inclusion of materials in the repository does not modify their
   copyright status in any way. Materials may be placed in:
   When you put anything in this directory, please send mail to
   giving us permission to distribute the files, and state whether
   this permission is just for the AI Repository, or also includes
   publication on the CD-ROM version (Prime Time Freeware for AI).
   We would also appreciate if you would include a 0.doc file for your
   package; see /user/ai/new/package.doc for a template. (If you don't
   have the time to write your own, we can write it for you based on
   the information in your package.)

   The Scheme Section of the AI Repository is maintained by Mark Kantrowitz 

Scheme Repository at Indiana University:

   The Scheme Repository at Indiana University contains a Scheme
   bibliography, copies of the R4RS report and other papers, sample
   Scheme code for a variety of purposes, several utilities, and some
   implementations. The Scheme code includes code for calendar
   calculations, Earley parser, FORMAT for Scheme, a scheme version of
   the Gabriel benchmarks, Marc Feeley's minimal object support for
   Scheme, a Scheme pretty-printer, a Prolog interpreter written in
   Scheme, a random number generator in Scheme, an implementation of
   SCOOPS, code from Abelson and Sussman's SICP book, Aubrey Jaffer's
   IEEE/R4RS compliance test, an implementation of matrices, a Scheme
   implementation of the Common Lisp FORMAT function, a Scheme front end
   to Adobe Illustrator PostScript, and a LALR(1) parser (ZEBU).  The
   repository was established by Ozan S. Yigit and is currently
   maintained by David Eby and John Zuckerman. Send administrative
   requests to
   The repository is accessible by anonymous ftp at   []
   or by WWW to
   The repository is mirrored in INRIA, courtesy of Christian Queinnec
   [Ecole Polytechnique and INRIA-Rocquencourt],
   and also

Other Scheme Collections:

   Scheme Implementations may also be found at 
   The R4RS report is available in
   or as MIT AI Memo 848b (email ············ for more information).
   The swiss-ftp archive includes SCOOPS, CL2Scheme, extend-syntax,
   btree, Gabriel benchmarks, FORMAT for Scheme, etc.

   The GI (German Computer Science Society) Scheme Archive contains a
   variety of scheme programs, utilities, code from theses, and other
   materials. It also mirrors the Scheme Repository.  It is
   accessible by anonymous ftp to
   (login as 'ftp', giving your email address as the password).
      pub/scheme/gi                # GI Scheme Archive
      pub/scheme/yorku             # Internet Scheme Repository
   Direct questions to ······
   The GI Scheme Archive is supported by the German Computer Society Special
   Interest Group on AI programming and sponsored by the Bavarian AI Center
   FORWISS -- Research Institute for Knowledge Based Systems.

Subject: [1-10] Publicly Redistributable Scheme Software

   SLIB (Standard Scheme Library) is a portable scheme library that
   provides compatibility and utility functions for many of the
   standard scheme implementations, including Chez, ELK 2.1, GAMBIT,
   MITScheme, scheme->C, Scheme48, T3.1, VSCM and Scm4e. It is available by
   anonymous ftp from
   Now includes a FAQ file.

   TEST.SCM is an IEEE and R4RS conformance test suite.  It is available

   PSD (Portable Scheme Debugger) is available by anonymous ftp
   from Tampere University of Technology, Finland,
   With PSD, you can run a Scheme program in an Emacs buffer, set
   breakpoints, single step evaluation and access and modify the
   program's variables. It works by instrumenting the original source
   code, so it should run with any R4RS compliant Scheme. It has been
   tested with SCM and Elk 1.5, but should work with other Schemes with a
   minimal amount of porting, if at all. Includes documentation and
   user's manual. Written by Pertti Kellom\"aki, ··
   The Lisp Pointers article describing PSD (Lisp Pointers VI(1):15-23,
   January-March 1993) is available as

   SCLINT is a lint-like program for Scheme. It checks for consistency of
   indentation, syntax of special forms, and the number of arguments to
   primitive and most user-defined procedures. This is not a full
   implementation, but rather a quick hack. It is used in teaching
   programming at the Tampere University of Technology. It is available
   by anonymous ftp from
   For further information, write to Pertti Kellom\"aki <··>.

   A bibliography of work in functional programming can be obtained by 
   anonymous ftp from
   ( It uses a refer-like format with %T for title, %A
   for authors %I for a unique index entry %S for source (possibly a
   reference to another index) %K for keywords and %C for comments.
   Compiled by Tony Davie, <····>. [Email bounced, 7/7/93.]

   Scheme Utilities --
   [This collection seems to no longer be located on brokaw -- does
   anybody know the current location?]

   A collection of Scheme implementations of data structures and
   algorithms is available by anonymous ftp from
   as the file scheme-algorithms.tar. For more information, contact
   Pertti Kellom\"aki <··>. 

   6.001. The User's Manual, example code, and problem sets from MIT's
   course "Structure and Interpretation of Computer Programs" are 
   available by anonymous ftp from

   Steele's Constraint System. Chris Hanson's implementation of Steele's
   constraint system is available for anonymous ftp from []
   A compressed version is also stored there. The software is source code
   for MIT Scheme. It should run in release 7.1.3. Most of the MIT Scheme
   dependencies could be eliminated, but it also uses the following
   procedures which aren't in standard Scheme: error, bkpt, macros,
   dynamic binding, and string output ports. The code corresponds pretty
   closely to Guy Steele's PhD thesis implementation, which you can
   obtain in printed form from the MIT AI Lab publications office as
   AI-TR-595 for $15.00 (email ············ for more
   information). For more information, send email to Chris Hanson

   JACAL is a symbolic mathematics system for the simplification and
   manipulation of equations and single and multiple valued algebraic
   expressions constructed of numbers, variables, radicals, and algebraic
   functions, differential, and holonomic functions. In addition, vectors
   and matrices of the above objects are included.  JACAL is written in
   Scheme and requires SLIB. JACAL source is available via anonymous FTP
   from,, and
   Contact ······ for more information.
   Zebu 0.9 is an LALR(1) parser generator for Scheme written by 
   William M. Wells III. It lives in the Scheme Repository
   and works with PC-Scheme from TI and MIT C-Scheme 6.2 (but not with
   anything after 7.0). 

   Thomas is a compiler for the Dylan programming language.  The Thomas
   system is written in Scheme and runs under MIT's CScheme, DEC's
   Scheme->C, and Marc Feeley's Gambit.  It can run on a wide range of
   machines including the Macintosh, PC compatibles, Vax, MIPS, Alpha,
   and 680x0.  Thomas generates IEEE compatible Scheme code.  Thomas is
   available to the public by anonymous ftp at
   For more information on Thomas and Dylan, see part 4 of the Lisp FAQ.

   MATCH is a pattern matching macro package for Scheme.  Pattern
   matching allows complicated control decisions based on data structure
   to be expressed in a concise manner. This document describes several
   pattern matching macros for Scheme, and an associated mechanism for
   defining new forms of structured data. This macro package works with
   any Scheme that supports defmacro (which is obtainable by loading
   SLIB), such as Chez Scheme (release 4 or greater). MATCH is available
   by anonymous ftp from
   [] and includes the macro source code and documentation. A
   copy should be available from the Scheme Repository shortly.  For
   further information, write to Andrew Wright, <······>.

   Soft Scheme provides the benefits of static typing for dynamically
   typed Scheme.  Like a static type checker, a soft type checker infers
   types for variables and expressions.  But rather than reject programs
   containing untypable fragments, a soft type checker inserts explicit
   run-time checks to transform untypable programs to typable form.
   These run-time checks indicate potential program errors, enabling
   programmers to detect errors prior to program execution.  Soft type
   checking minimizes the number of run-time checks in the compiled code,
   enabling dynamically typed languages to attain the efficiency of
   statically typed languages like ML. Soft Scheme is available by
   anonymous ftp from []
   For more information, write to Andrew Wright <······>.

   ChezSybase is a Chez Scheme interface to the Sybase database.
   It uses the Chez Scheme foreign function interface to provide a
   high-level Scheme interface to the Sybase db-lib (the API to the
   Sybase database). Most of the db-lib calls and datatypes are
   supported, with the possible exception of spotty support for text and
   image data, and there is no analog to the datetime datatype. It is
   available by anonymous ftp from
   For more information, write to Karl O. Pinc <···>.

Subject: [1-11] Formatting code in LaTeX

SLaTeX is a R4RS-compliant Scheme program that allows you to write
program code "as is" in your LaTeX or TeX source.  It is particularly
geared to the programming languages Scheme and Common Lisp, and has
been tested in Chez Scheme, Common Lisp, MIT C Scheme, Elk, Scheme->C,
SCM and UMB Scheme on Unix; and MIT C Scheme and SCM on MSDOS.  The
formatting of the code includes assigning appropriate fonts to the
various tokens in the code (keywords, variables, constants, data), at
the same time retaining the proper indentation when going to the
non-monospace (non-typewriter) provided by TeX.  SLaTeX comes with two
databases that recognize the standard keywords/variables/constants of
Scheme and Common Lisp respectively.  These can be modified by the
user using easy TeX commands.  In addition, the user can inform SLaTeX
to typeset arbitrary identifiers as specially suited TeX expressions
(i.e., beyond just fonting them).  The code-typesetting program SLaTeX
is available by anonymous ftp from
Send bug reports to ·····

SchemeWEB provides simple support for literate programming in Lisp.
SchemeWEB version 2.0 is a Unix filter that allows you to generate
both Lisp and LaTeX code from one source file.  The generated LaTeX
code formats Lisp programs in typewriter font obeying the spacing in
the source file.  Comments can include arbitrary LaTeX commands.
SchemeWEB was originally developed for the Scheme dialect of Lisp, but
it can easily be used with most other dialects.  Version 2.0 is
available in the Scheme Repository as
or in the Comprehensive TeX Archive Network (CTAN) in the directory 

The Literate Programming FAQ lists a number of alternatives, both
language-independent and Scheme-specific. The Literate Programming FAQ
is posted once a quarter to the comp.programming.literate newsgroup
and is available by anonymous ftp from A copy may also be
requested by sending an email message to ········
   sendme litprog.faq
in the body of the message.

Subject: [1-12] Where can I get an implementation of Prolog in Scheme?

   Prolog in Scheme is a collection of macros that expand syntax for
   clauses, elations, and so on. It is written in Scheme and has support
   for delayed goals and interval arithmetic. It is known to run in Chez
   Scheme and in Elk, and is intended to be portable to other Scheme
   implementations. It relies on continuations, and so is not easily
   ported to Common Lisp. Available from the University of Calgary by
   anonymous ftp from
   Questions and comments may be addressed to Alan Dewar
   <·····> or John Cleary <·······>.

   Schelog is an embedding of Prolog in Scheme. It represents Prolog
   goals as procedures in Scheme, and includes macros to simulate a
   Prolog-style syntax for clauses, relations and queries.  The embedding
   permits the user to combine Prolog and Scheme code freely, in the same
   s-expression, if desired.  Documentation and examples are included.
   Schelog should run in any R4RS Scheme, has been tested in SCM and Chez
   Scheme, and will run in any Scheme implementation that supports SLIB (see
   entry in [1-10] above).  Schelog (version 2) is available by anonymous
   ftp from  Its use of
   higher-order continuations is probably a major obstacle to porting it
   to Common Lisp.  For more information, please contact the author Dorai
   Sitaram <·····>.

Subject: [1-13]  What does SICP, SCOOPS, R4RS, CAR, CDR, ... mean?

Glossary of acronyms:
   CAR             Originally meant "Contents of Address portion of Register",
                   which is what CAR actually did on the IBM 704.
   CDR             Originally meant "Contents of Decrement portion of 
                   Register", which is what CDR actually did
                   on the IBM 704. Pronounced "Cudder".
   ANSI            American National Standards Institute
   SICP            Abelson and Sussman's book "Structure and
                   Interpretation of Computer Programs".
   EOPL            Essentials of Programming Languages 
   SCOOPS          An experimental object-oriented programming
                   language for Scheme.
   R3RS            Revised^3 Report on the Algorithmic Language Scheme.
   R4RS            Revised^4 Report on the Algorithmic Language Scheme.

Subject: [1-14] Why is there no EVAL in Scheme?

The answer to this question is based on information provided by 
Guillermo J. Rozas and Aubrey Jaffer.

There are three major positions in the Scheme community regarding EVAL:

   1. No EVAL: EVAL is antithetical to a Pascal-like (compiler based,
      externally statically linked) implementation for Scheme, such as
      some people have or wish to see. 

   2. Single Argument: There is a single distinguished top-level
      environment, and EVAL always evaluates its argument there. 
      (This is the approach taken in Common Lisp, where EVAL evaluates
      its argument in the current dynamic environment and in a null
      lexical environment.) 

   3. Two Arguments: There are multiple environments in which
      the user might want to evaluate expressions, so EVAL should take
      two arguments, the second being an environment.  In particular,
      in some systems with first-class environments, there is no
      a-priori single distinguished top-level environment, and
      defaulting the environment does not fit those dialects well.

Not every dialect of Scheme has EVAL. Most do, but some with different
names and arguments. Jaffer's SLIB package uses LOAD as defined in
R4RS to define EVAL for those implementations that don't support EVAL
(e.g., by writing the code out to a file and then loading it).
Rozas's compromise proposal for EVAL was accepted for R5RS, but it is
unclear whether there will ever be a R5RS.

Subject: [1-15] World-Wide Web (WWW) Resources

The World Wide Web (WWW) is a hypermedia document that spans the
Internet.  It uses the http (HyperText Transfer Protocol) for the
light-weight exchange of files over the Internet.  NCSA Mosaic is a
World Wide Web browser developed at the National Center for
Supercomputing Applications (NCSA). 

Mosaic's popularity derives, in part, from its ability to communicate
using more traditional Internet protocols like FTP, Gopher, WAIS, and
NNTP, in addition to http. Mosaic can display text, hypertext links,
and inlined graphics directly. When Mosaic encounters a file type it
can't handle internally, such as Postscript documents, mpeg movies,
sound files, and JPEG images, it uses an external viewer (or player)
like Ghostscript to handle the file. Mosaic also includes facilities
for exploring the Internet. In other words, Mosaic is an multimedia
interface to the Internet.

The hypertext documents viewed with Mosaic are written in HTML
(HyperText Markup Language), which is a subset of SGML (Standard
Generalized Markup Language).  All that is needed is just a few more
improvements, such as the ability to format tables and mathematics,
and a WYSIWYG editor, for HTML to greatly facilitate electronic
journals and other publications.

NCSA Mosaic for the X Window System is available by anonymous ftp from
as source code and binaries for Sun, SGI, IBM RS/6000, DEC Alpha OSF/1, DEC
Ultrix, and HP-UX. Questions about NCSA Mosaic should be directed to 
········ (X-Windows version), ··········
(Macintosh), and ·········· (Microsoft Windows).

A simple HTML version of the Scheme FAQ (this FAQ) is available as

The Scheme home page at MIT is
It includes a nifty little form that lets you execute small examples
of Scheme code.

The Scheme Underground web page is

Subject: [1-16] Why is Scheme called 'Scheme'?

According to Steele and Gabriel's "The Evolution of Lisp" paper,
Scheme was originally called Schemer, in the tradition of the AI
languages Planner and Conniver. But the ITS operating system had a
6-character limitation of file names, so the names were shortened to
PLNR, CNVR, and SCHEME. Eventually the truncated name Scheme stuck.

;;; *EOF*
From: Mark Kantrowitz
Subject: FAQ: Scheme Implementations and Mailing Lists 2/2 [Monthly posting]
Message-ID: <SCHEME_2_858240016@CS.CMU.EDU>
Archive-name: scheme-faq/part2
Last-Modified: Wed Nov 13 15:17:02 1996 by Mark Kantrowitz
Version: 1.31
Maintainer: Mark Kantrowitz and Barry Margolin <···········>
Size: 49592 bytes, 880 lines

;;; ****************************************************************
;;; Answers to Frequently Asked Questions about Scheme *************
;;; ****************************************************************
;;; Written by Mark Kantrowitz and Barry Margolin
;;; scheme_2.faq

This post contains part 2 of the Scheme FAQ.

If you think of questions that are appropriate for this FAQ, or would
like to improve an answer, please send email to us at ···········

Topics Covered (Part 2):
  [2-1]   Free Scheme implementations.
  [2-2]   Commercial Scheme implementations.
  [2-3]   What Scheme-related discussion groups and mailing lists exist?

Search for \[#\] to get to question number # quickly.

Subject: [2-1] Free Scheme implementations.

Repositories of Scheme source code are described in the answer to
question [1-9].

Remember, when ftping compressed or compacted files (.Z, .z, .arc, .fit,
etc.) to use binary mode for retrieving the files. 

Files that end with a .z suffix were compressed with the patent-free
gzip (no relation to zip). Source for gzip is available from:
as the files gzip-1.2.4.shar, gzip-1.2.4.tar,or gzip-1.2.4.msdos.exe.

Repositories of Scheme implementations:

   Many free Scheme implementations are available from
   []. See also the Scheme Repository described below.

   The Scheme Repository contains a Scheme bibliography, copies of the
   R4RS report, sample Scheme code for a variety of purposes, several
   utilities, and most free implementations.  (Implementations of Scheme
   available from the repository include elk, gambit, scm, fools, rabbit,
   s48, scheme84, scheme88, pseudo, xscheme, umb-scheme, siod, vscm, and
   pixiescheme.) The repository was established by Ozan S. Yigit and
   is currently maintained by David Eby and John Zuckerman
   <·························>. The repository is
   accessible by anonymous ftp at   []
   The repository is mirrored in INRIA, courtesy of Christian Queinnec
   [Ecole Polytechnique and INRIA-Rocquencourt],
   (See also [1-9].)

Scheme implementations:

   BIGLOO is a Scheme interpreter and compiler. It conforms to the
   IEEE-Scheme standard (IEEE P1178) with some extensions, such as
   regular expression parsing (RGC), a lexical analyzer generator, a full
   foreign function interface, and a pattern matching compiler.  Bigloo
   can also compile modules written in Caml (an ML dialect), letting you
   mix Scheme, ML, and C.  Object-oriented programming is provided by
   Meroon v3. The main goal of Bigloo is to deliver small and fast stand
   alone applications.  Bigloo produces ANSI C and hence should be easy
   to port. It runs on Sparc (1, 2, 10), SONY-NEWS (MIPS R3000), IRIS
   Indigo (MIPS R3000), Sun 3/60, DecStation 3100, PC-486 (linux), and
   HP-PA (730).  It is available by anonymous ftp from []
   as the files bigloo1.7.tar.gz and camloo0.2.tar.gz.
   For further information, send email to ··············, or
   write to Manuel Serrano (equipe ICSLA, Bat 8), INRIA-Rocquencourt, 
   BP 105, 78153, Le Chesnay CEDEX, FRANCE, or call 39-63-57-32.

   Elk (Extension Language Kit) has been designed specifically as an
   embeddable, reusable extension language subsystem for applications written
   in C or C++.  Elk is also useful as a stand-alone Scheme implementation,
   in particular as a platform for rapid prototyping of X11-based Scheme
   programs.  Elk was first published in 1989; the current version is Elk 3.0.
      The Elk distribution includes a Scheme interpreter (embeddable and
   stand-alone versions), several dynamically loadable extensions, run-time
   support (including a top-level implemented in Scheme and a debugger),
   and 230+ pages of documentation (troff and PostScript format).
      Major features of Elk are incremental, dynamic loading of compiled
   extensions (supported on many platforms); freezing of the interpreter or
   application into a new executable file; a C/C++ programmer's interface
   for language interoperability; Scheme bindings for X11 Xlib, Xt, Athena
   and Motif Widgets; a UNIX interface (not restricted to POSIX); bitstrings,
   records, and regular expressions; a stop-and-copy and an incremental,
   generational garbage collector.
      The Elk 3.0 distribution and more information about Elk are available
   in the World Wide Web at
   The distribution is also available on a number of FTP sites including
   For more information contact Oliver Laumann <···>.

   FDU Scheme is a R3RS implementation of Scheme for the Prime
   50-series under Primos. It is available by anonymous ftp from [] (username "anonymous", password
   <RETURN>). Attach to the Scheme subdirectory (cd '*>scheme') and
   transfer all files in it and its subdirectories using file type
   binary.  For more information, contact Peter Falley,

   Fools' Lisp is a small Scheme interpreter that is R4RS conformant, and
   is available by anonymous ftp from [] 
   Fools' Lisp runs on Sun3 and Sun4 (SunOs), DecStation 3100s, Vax
   (Ultrix), Sequent, and Apollo. Implemented by Jonathan Lee

   Gambit is a high-performance implementation of Scheme based on an
   optimizing compiler.  It conforms to the IEEE-Scheme standard (IEEE
   P1178) and the Revised^4 Report on Scheme (R4RS) and supports the
   whole numeric tower (i.e. integer, rational, real and complex numbers).
   Gambit extends the standards by providing: weak pairs, wills, string
   ports, records, property lists, namespaces, futures, pretty printer,
   debugger, multitasking, and compiler declarations.  To make it portable
   and simplify bootstrapping, the compiler is written in IEEE-Scheme and
   makes use of a high-level abstract-machine (called GVM) for the
   intermediate representation.  A "Scheme-in-Scheme" approach was adopted
   to minimize the amount of non-portable code in the system (nearly all of
   the runtime library is written in Scheme including the interpreter and
   debugger).  Three different variants of Gambit were produced:

   Gambit-68K (first public release in 1990; last version: 2.0, june 1993):
     This is the original Gambit system with a native code back-end
     for Motorola 680x0.  It works on most 68K based Unix workstations
     and on the BBN GP1000 shared-memory multiprocessor.  The back-end
     for the GP1000 implements Multilisp's "future" parallel construct
     using lazy-task-creation (a very low overhead task spawning

   MacGambit (first public release in 1991; last version: 2.2.2, oct 1995):
     This is a port of Gambit-68K for the Macintosh.  It is a complete
     development environment, including a Scheme-aware editor, an online
     help system, and a linker to build standalone applications.  A
     drawing window for simple graphics and an interface to many of the
     Macintosh's "Toolbox" routines are available.  An executable
     MacGambit application is supplied with the distribution as well as
     all the sources (ThinkC 4.0 or CodeWarrior 6 or higher are needed to
     recompile the sources).

   Gambit-C (first public release in 1994; last version: 2.3.1, april 1996):
     In this variant of Gambit, the compiler generates highly portable
     C code that is reasonably efficient.  The primary goals of Gambit-C
     are portability and correctness (in particular it correctly implements
     tail-recursion across modules and uses a precise garbage-collector).
     Gambit-C runs on a wide range of Unix workstations, on Macintosh, and
     DOS/Windows.  It also supports these features: dynamic-loading
     of compiled files, C-interface (FFI), and a memory management system
     that expands and contracts the heap based on the program's needs.
     Standalone executables can be created with Gambit-C (a minimal
     application is about 700 Kbytes when statically linked and 5 Kbytes
     when the runtime system is compiled as a shared-library).
     Executables for Windows-95 and Windows-NT:
     Executables for DOS and Windows 3.1:

   Gambit can be used freely for non-commercial uses (including academic
   research and education).  A license is required to use Gambit
   commercially (contact ······

   HELP (a lazy Scheme) is available by anonymous ftp from  Written by
   Thomas Schiex (······, ······ Help is a complete and
   efficient Scheme-like functional lazy Lisp interpreter.  It works only
   on 68020 (or more) based Macintoshes. It has a 'friendly' interface
   (parenthesis matcher, auto-indent), uses a full call-by-need semantics
   and includes many examples, including a symbolic compiler for the
   680x0. Efficiency is good and lazyness is fully parametrizable (you
   may turn Help into a strict Scheme-like language if you like). French
   AND English updated docs are included in Word4 and plain text formats.

   LIBSCHEME is a C library implementing Scheme as described in R4RS.  It
   is easily integrated into a C program as a command interpreter or
   extension language, and is easily extended in C with new primitive
   types, primitve functions and syntax.  It should be portable to most
   machines with an ANSI C compiler. It is available by anonymous ftp
   For more information, write to Brent Benson

   MIT Scheme (aka C-Scheme), is available free by anonymous FTP from []
   Version 7.3 is a beta version and runs on DEC Alpha, DECStation
   (MIPS), HP 9000 300/400/700, IBM RS-6000, Intel i386/i486 (DOS, NT,
   Windows 3.1, or Linux), NeXT (NeXTOS 2 or 3), SGI (MIPS), Sony NEWS
   (MIPS), Sun3 (SunOS 4.1) and Sun4 (SunOS 4.1).  Bugs should be
   reported to ··········· (for the DOS version, send
   bug reports to ···············  MIT Scheme
   includes Edwin (Scheme's Emacs-like editor) and Liar (the Scheme
   compiler). Does not have a convenient foreign function interface yet.
   FTP distribution includes MIT C-Scheme Reference and User manuals, as
   well as the Revised^4 Report on Scheme. Discussion occurs on the
   newsgroup comp.lang.scheme.c (gatewayed to the mailing list
   ············ For DOS floppy distribution requests
   (includes printed copies of manuals), send $95.00 (payable in U.S.
   funds to "Scheme Distribution") to cover costs of distribution to
   Scheme Distribution, c/o Prof. Hal Abelson, 545 Technology Sq. rm 410,
   Cambridge MA 02139, USA.
   On the NeXT, MIT Scheme is available as part of the Schematik
   package, which provides an editor/front-end user interface,
   graphics, and "robotics" support for Lego and the like.  Schematik is
   free and is available for anonymous ftp from
   Europeans can get it more locally from
   start with Schematik- .  Schematik is also apparently
   included on NeXT's "Educational Software Sampler" CD-ROM.
   A preliminary unofficial port of C-Scheme to the Linux is available 
   from Contact the author
   Matteo Frigo <············> for more information. 

   MzScheme is a Scheme implementation for Unix, Windows (Win32), and
   MacOS. In addition to supporting standard R4RS Scheme (including the
   full numerical tower), MzScheme provides pre-emptive threads,
   generative record datatypes, an exception system (integrated with all
   primitive errors), classes and objects, first-class compilation units,
   regular expression parsing, and simple TCP support on all platforms.
     MzScheme can dynamically load extensions implemented in C, and it
   can be embedded into any C/C++ application. Interoperability with C is
   facilitated by the use of a conservative garbage collector.
     MzScheme is the core interpreter for MrEd, an engine for developing
   portable GUI applications for X Windows, Windows, and MacOS. DrScheme
   (currently under development, using MzScheme/MrEd) will incorporate
   project management, debugging, and modular analysis to provide a
   complete Scheme development environment for pedagogical and
   professional use.
     For information and online documentation for MzScheme, MrEd, and 
   DrScheme, see

   Oaklisp is an seamless integration of Scheme with an object-oriented
   substrate. Available by anonymous ftp from []
   or from
   and includes reference and implementation manuals. Written by Barak
   Pearlmutter <···> and Kevin Lang <·····>.

   PC-Scheme (aka PCScheme, PC Scheme) is an implementation of Scheme
   originally written by Texas Instruments. TI made a version of the
   source code freely distributable in 1987. TI stopped supporting
   the code, and some researchers at the University of Geneva produced
   a cleaned-up version (see PCS/Geneva below). On July 13, 1992, Ibuki
   announced that it had purchased the rights to PC Scheme from TI.
   Please see the Ibuki PC Scheme entry in [2-2]. If you want a
   high-quality and supported implementation of PC Scheme, buy the
   Ibuki implementation. It is certainly inexpensive enough. Now TI
   PC-Scheme is available by anonymous ftp from
   and runs on MS-DOS 286/386 IBM PCs and compatibles. Version 3.3 
   should run on the 486, but no guarantees. Version 3.3 is the last
   free version. TI PC-Scheme conforms to the Revised^3 Report on Scheme.
   It includes an optimizing compiler, an emacs-like editor, inspector,
   debugger, performance testing, foreign function interface, window
   system and an object-oriented subsystem. It also supports the dialect
   used in Abelson and Sussman's SICP.

   PCS/Geneva is a cleaned-up version of Texas Instrument's PC Scheme
   developed at the University of Geneva. The main extensions to PC
   Scheme are 486 support, BGI graphics, LIM-EMS pagination support, line
   editing, mouse support, assembly-level interfacing, and several
   powerful Scheme-oriented editors. (TI's PC Scheme gives users full
   Revised^3 support along with many primitives for DOS, Graphics and
   Text Windows. A powerful built-in optimizing compiler produces fast
   code.) PCS/Geneva 4.02PL1 has been tested on XTs, ATs, AT386s and
   AT486s under various DOS and OS/2 versions. It even runs on
   Hewlett-Packard's HP95LX. It also runs on Suns with a DOS emulator.
   PCS/Geneva is available free by anonymous ftp from []
   as the files pcscheme.doc, pcscheme.exe, pcscheme.fil and pcscheme.taz
   or by email (uuencoded) from ········ If you ftp
   PCS/Geneva, please send mail to ········; the authors
   like to know their public and will inform you when a new release is
   available. This is also the email address for bug reports or if you
   need any kind of help. This product may be distributed freely and
   used without restrictions except for military purposes.
   (PCS/Geneva was developed by Larry Bartholdi <·······>
   and Marc Vuilleumier <········>.)

   Pixie Scheme for the Macintosh is a nearly complete implementation of
   R3RS available by anonymous ftp from 
     PixieScheme.NoFPP.SIT.bin  ; for macs without floating-point coprocessor
     PixieScheme.SIT.bin        ; for macs with FPP
   Written by Jay Reynolds Freeman <·······@MasPar.COM>, P. O. Box 60628,
   Palo Alto, CA, 94306-0628. A copy may also be obtained from
   as the file pixiescheme.cpt.hqx if your site runs the Andrew File System,
   or by anonymous ftp from

   Scheme->C is an R4RS compliant Scheme system that is centered around
   a compiler that compiles Scheme to C.  Besides the base language,
   the system includes "expansion passing style" macros, a foreign function
   call capability, records, weak pointers, 3 X11 interfaces, call/cc, and a
   generational, conservative, copying garbage collector. The result is a
   system that is portable, efficient, and able to build applications that
   contain a mix of compiled and interpreted Scheme, and compiled code
   from C, C++ and other languages.  The current release of Scheme->C runs
   on the following systems: Digital Alpha AXP systems with OSF/1, MIPS
   based DECstations, VAXen with ULTRIX, MIPS based SGI systems, PC's 
   running Microsoft Windows 3.1, Apple Macintosh's running system 7.1,
   HP 9000/300, HP 9000/700, Sony News, Harris Nighthawk and other m88k
   systems, linux, Sun SPARC, and NT (Visual C++ compiler).  Earlier 
   releases also run on Sun3, DNx500, DN1000, 386's running Unix,
   DNx500, and DN1000 systems.  The software is available for
   anonymous ftp from []
   There are three interfaces to X11, all written in Scheme, available
   from gatekeeper. The first is a complete set of stubs to Xlib included
   in the base system.  The second is an alternative to Xlib called SCIX,
   found in
   The third, ezd, allows programs to easily
   produce interactive, structured graphics and is found in
   Those without ftp access can also obtain Scheme->C and ezd from the
   Prime Time Freeware CD, Vol. 1, No. 2.  Additional information is
   available from the author at Digital Equipment Corporation's Western
   Research Lab: Joel Bartlett, ········

   Scheme 48 is a Scheme implementation based on a virtual machine
   architecture. Scheme 48 is designed to be straightforward, flexible,
   reliable, and fast. It should be easily portable to 32-bit
   byte-addressed machines that have POSIX and ANSI C support.
   In addition to the usual Scheme built-in procedures and a development
   environment, library software includes support for hygienic macros (as
   described in the Revised^4 Scheme report), multitasking, records,
   exception handling, hash tables, arrays, weak pointers, and FORMAT.
   Scheme 48 implements and exploits an experimental module system
   loosely derived from Standard ML and Scheme Xerox.  The development
   environment supports interactive changes to modules and interfaces.
   A beta release of Scheme 48 is available by anonymous ftp from
   For more information, contact Richard Kelsey and Jonathan Rees
   at <·················>.

   Scsh is a Unix shell/systems programming environment implemented on top of
   Scheme 48 (a portable, byte-code compiled R4RS Scheme implementation). Scsh

       - A high-level macro notation for writing typical shell-script 
	 computations: running programs, pipelines, I/O redirection, and so 
	 forth. For example, to decompress a file and mail it to someone, 
	 you might say
	   (run (| (gzcat home.html.gz) 
		   (mail -h "Here's my home page" ·······

	 To spell check your paper, printing out the results, you could say:
	   (run (| (delatex (< paper.tex))
		   (lpr -Ppulp)))

       - A complete system-call interface to Unix: fork, exec, I/O, file
	 system, time, env vars, and so forth. The I/O interface includes
	 a *complete* interface to BSD sockets, both Unix and TCP/IP domains.
	 I/O is completely integrated with Scheme ports. System calls return
	 useful values, not error codes; errors are reported by raising
	 exceptions which can be caught by handlers.

       - Other useful shell-programming utilities: filename globbing/pattern
	 matching, regexp matching, macros for writing AWK-like programs, field
	 and record parsers, and so forth.

       - The ability to write executable shell scripts using the Unix #!
	 interpreter feature, with access to command-line argv values.

   These features are completely integrated into Scheme 48's R4RS Scheme
   implementation; the programming language is Scheme. The scsh release
   is self-contained -- it comes with its own complete Scheme 48
   implementation. Scsh currently runs on the following platforms: DEC Ultrix,
   Harris NightHawk, HP-UX, IBM AIX, Linux, NetBSD/i386, NeXTSTEP/Intel,
   SGI IRIX, Solaris, and SunOS. It's not hard to port scsh to new systems.
   You can get a copy of scsh via anonymous ftp, from the following:
   These tar files include a detailed manual and a paper describing
   the design of the system. For the lazily curious, we also have the
   manual separately available as
   Scsh has been implemented by the Scheme Underground
   For further information, contact Olin Shivers <·······>,

   SCM, free by anonymous ftp from
   Current version 4e1. Runs on Amiga, Atari-ST, MacOS, MS-DOS, OS/2,
   NOS/VE, VMS, Unix and similar systems. SCM conforms to the Revised^4
   Report on the Algorithmic Language Scheme and the IEEE P1178
   specification. Scm is written in C.  ASCII and EBCDIC are supported.
   Written by Aubrey Jaffer.
      To receive an IBM PC floppy disk with the source files and MSDOS
   and i386 executables send $99 to Aubrey Jaffer, 84 Pleasant Street,
   Wakefield MA 01880, <······>. 
      SLIB (Standard Scheme Library) is a portable Scheme library
   which is intended to provide compatability and utility functions for
   all standard Scheme implementations, including SCM, Chez, Elk,
   Gambit, MacScheme, MITScheme, scheme->C, Scheme48, T3.1, and VSCM, and is
   available as the file slib2a0.tar.gz. Written by Aubrey Jaffer.
      JACAL is a symbolic math system written in Scheme, and is
   available as the file jacal1a4.tar.gz. 
      SCMCONFIG contains additional files for the SCM distribution to build
   SCM on Unix machines using GNU autoconf.
      SLIB-PSD is a portable debugger for Scheme (requires emacs editor).
      TURTLSCM is a turtle graphics package which works with SCM on MSDOS
   or X11 machines. Written by Mkinen Sami <···> and Jarkko
   Leppanen <···>, it is available as the file turtlegr.tar.Z.
   (Also available from as turtlegr.tar.gz,
   along with an already-compiled MSDOS binary of scm with turtlegraphics
   and slib in
      XSCM is an X Windows interface to Xlib and the Motif and
   OpenLook toolkits for the SCM interpreter. It requires scm4a10 or
   later. It should be available at any archive of alt.sources, or on
   swiss-ftp, prep and indiana as the file xscm1.05.tar.Z.
   Contact ········ for more information.
      SMG-SCM is a package that adds VMS SMG screen management routines
   to SCM. It is available from swiss-ftp, prep and indiana as the file (A VMS version of Unzip is available by anonymous
   contains the source code, documentation, and example code. Send
   comments and bugs to T. Kurt Bond, <···> (preferred)
   or <·········>.
      WB is a disk based, sorted associative array C library (database). These
   associative arrays consist of variable length (less that 256 bytes)
   keys and values.  WB comes with an interface to SCM. Basic
   operations are creation, destruction, opening and closing of 
   diskfiles and arrays, insertion, deletion, retrieval, successor, and
   predecessor (with respect to dictionary order of keys).  Functional
   application of find-next, deletion, and modification over a range of
   consecutive key values is supported. Multiple associative arrays
   can be stored in one disk file. Simultaneous access to multiple
   disk files is supported.  A structure checker, garbage collector
   are included.  A repair program and ram-disk type file (for
   temporary structures) are in developement. The current WB
   implementation has a file size limit of 2^32 * block size (default
   2048) = 2^43 bytes (8796 Gbytes). WB does its own memory and disk
   management. WB is available on swiss-ftp, prep, and indiana as wb1a1.tar.z.

      A Windows version of Scheme called WinScm is forthcoming from
   Vincent Manis of Langara College of BC, Canada. 

      Hobbit is a Scheme-to-C compiler that works with the SCM Scheme
   interpreter. It treats SCM as a C library and integrates compiled
   functions into SCM as new primitives. Hobbit release 2 works with SCM
   release 4b4. Future releases of SCM and Hobbit will be coordinated.
   Hobbit imposes strong restrictions on the higher-order features of
   Scheme. For example, it does not support continuations.  The main aim
   of hobbit is to produce maximally fast C programs which would retain
   most of the original Scheme program structure, making the output C
   program readable and modifiable. Hobbit is written in Scheme and is
   able to self-compile. Hobbit can be obtained via anonymous ftp from
   For further information, contact the author, Tanel Tammet, at
   <······> or at Tanel Tammet, Department of Computer
   Sciences, Chalmers University of Technology, S-41296 Go"teborg, Sweden.

   Similix is a Self-Applicable Partial Evaluator for a Subset of Scheme.
   Written by Anders Bondorf, Olivier Danvy, and Jesper J{\o}rgensen. It
   is available by anonymous ftp from 
   as similix.tar.Z or from For 
   more information, contact Anders Bondorf, DIKU, Department of Computer
   Science, University of Copenhagen, Universitetsparken 1, DK-2100
   Copenhagen, Denmark, or send email to ······ Similix conforms
   to the IEEE and R4RS standards, but also runs under R3RS Scheme. It
   runs in SCM, Chez Scheme and T3.1.

   SIOD (Scheme in One Defun), free by anonymous ftp from
   or in any comp.sources.unix archive.  Runs on VAX/VMS, VAX UNIX, Sun3,
   Sun4, Amiga, Macintosh, MIPS, Cray, Windows NT/WIN32.  Small scheme
   implementation in C arranged as a set of subroutines that can be
   called from any main program for the purpose of introducing an
   interpreted extension language.  Compiles to ~42K bytes of
   executable.  Lisp calls C and C calls Lisp transparently. Version
   3.0 includes support for manipulation of Oracle and Digital RDB
   relational databases (SQL interface). 
   Written by George Carrette <···> or <···>.

   STk is a R4RS Scheme interpreter which can access the Tk graphical
   package. All of the commands defined by the Tk toolkit are available
   to the STk interpreter, and Tk variables are reflected back into
   Scheme as Scheme variables. Callback is expressed in Scheme. Includes
   a CLOS-like OO extension called STklos, which provides multiple
   inheritance, generic functions, multi methods, and a true meta-object
   protocol.  A set of classes have been defined to manipulate Tk
   commands (menu, buttons, scales, canvas, canvas items) as Scheme
   objects. STk runs on Sparc (SUNOS 4.1.x), Dec 5xxx (Ultrix 4.2), SGI
   (Irix 4.05, 5.1.1), DEC Alpha, and Linux 1.0. STk is available by
   anonymous ftp from []
   Please send bug reports, comments, and questions to Erick Gallesio,
   <··>, Universite de Nice - Sophia Antipolis, ESSI - I3S
   Route des colles, BP 145, 06903 Sophia Antipolis CEDEX, FRANCE,
   phone (33) 92-96-51-53, fax (33) 92-96-51-55.
   To subscribe to the mailing list, send a message with 
   in the Subject field to ···········

   T3.1 is a Scheme-like language developed at Yale. Available by
   anonymous ftp from
   T may be obtained in Europe from
   Runs on DecStations (MIPS processor) and SGI Iris, Sun4
   (SPARC), Sun3, Vax/Unix. Includes a copy of the online version of the
   T manual and release notes for T3.0 and T3.1. All implementations
   include a foreign function (C) interface. To be informed of fixes, new
   releases, etc., send your email address to ········· Bug
   reports should go to ······· A multiprocessing version of
   T (for Encore Multimax) is available from
   [The sources were last modified November 22, 1991.]

   UMB Scheme is a R4RS Scheme available by anonymous ftp from and also in the Scheme
   Repository. It includes a simple editor, debugger, Written by William
   Campbell, University of Massachusetts at Boston, ····

   VSCM is a R4RS Scheme available by anonymous ftp from the Scheme Repository, []
   Written by Matthias Blume, <·····>. The
   implementation is based on a virtual machine design with heavy support
   for most of the sophisticated features of Scheme. The virtual machine
   is written in ANSI-C to aid in its portability. The bytecode compiler
   is written in Scheme itself. Documentation of VSCM is also available as

   XScheme is available free by anonymous ftp from
   It includes an object system and is R3RS compliant.
   It was written by David Michael Betz, 167 Villa Avenue #11, Los Gatos,
   CA 95032, 408-354-9303 (H), 408-862-6325 (W), ·····
   XScheme is discussed in the newsgroup comp.lang.lisp.x.  It may also
   be found in the Scheme Repository.

Free Scheme Implementations implemented in Lisp:  

   Peter Norvig's book "Paradigms of AI Programming" has a chapters about
   Scheme interpreters and compilers, both written in Common Lisp. The
   software from the book is available by anonymous ftp from and on disk in Macintosh or DOS format from
   the publisher, Morgan Kaufmann.  For more information, contact: Morgan
   Kaufmann, Dept. P1, 2929 Campus Drive, Suite 260, San Mateo CA 94403,
   or call Toll free tel: (800) 745-7323; FAX: (415) 578-0672

   PseudoScheme is available free by anonymous ftp from
   It is Scheme implemented on top of Common Lisp, and runs in Lucid,
   Symbolics CL, VAX Lisp under VMS, and Explorer CL. It should be
   easy to port to other Lisps. It was written by Jonathan Rees
   (···, ··· Send mail to
   ····················· to be put on a mailing list
   for announcements. Conforms to R4RS except for lacking a correct
   implementation of call/cc. It works by running the Scheme code
   through a preprocessor, which generates Common Lisp code. 

   Scheme84 is in the public domain, and available by mail from Indiana
   University. It runs on the VAX in Franz Lisp under either VMS or BSD Unix.
   To receive a copy, send a tape and return postage to: Scheme84
   Distribution, Nancy Garrett, c/o Dan Friedman, Department of Computer
   Science, Indiana University, Bloomington, Indiana. Call 1-812-335-9770
   or send mail to ··· for more information. It will also
   run in Jeff Dalton's port of Franz Lisp to Net/Free/386BSD on 386-like
   machines.  (See the Lisp FAQ for information on Franz Lisp.)
   Scheme84 is available by anonymous FTP from

   Scheme88 is available by anonymous ftp from
   and also from the Scheme Repository.

Subject: [2-2] Commercial Scheme implementations.

Chez Scheme:

   Chez Scheme Version 5 is a high-performance implementation of Scheme
   conforming to the IEEE/ANSI Scheme Standard and the R4RS.  Chez Scheme
   provides an incremental optimizing compiler, complete run-time library,
   generation-based garbage collector, interactive inspector, and C
   interface.  New Version 5 features include improved performance,
   lexical macros, multiple values, shared incremental heaps, guardians
   and weak pairs, and generic ports.  Version 5 is available for Sparc
   SunOS and Solaris, Alpha OSF/1, SGI IRIX 5.X, Motorola mc88000 SVR3/4,
   80386 NeXT Mach, BSDI BSD/386, and Linux.  More information on Chez
   Scheme can be obtained via anomymous ftp from
   Site license fees start at $9000 ($4500 academic).  We are not able to
   handle personal sales at this time.  For detailed pricing and ordering
   information contact ····· or Kent Dybvig at
   ···  Cadence Research Systems, 3814 Devonshire South,
   Bloomington, IN 47408-9698, USA.  Phone 812-333-9269, fax 812-332-4688.

EdScheme, WinScheme Editor, 3DScheme, "The Schemer's Guide", and 
"The Schemer's Guide to C++":

   Schemers Inc. publishes software and textbooks that promote the
   use and advancement of Scheme in the educational and commercial
   sectors. Their products include:

   +  The WinScheme Editor v2.0. This is a Windows full-featured MDI
      (Multiple Document Interface) editor for Scheme programs. It knows
      about Scheme syntax and contains comprehensive code formatting
      facilities. It provides a channel for sending programs direct to
      Windows-based Scheme interpreters, allowing users to develop, test,
      and edit Scheme code from within the editor. The WinScheme Editor
      also includes a substantial set of context-sensitive online
      documentation for the programming environment and the Scheme
      language.  The WinScheme Editor requires MS Windows 3.1 or later (with
      Win32s), Windows 95 or Windows NT with 2MB RAM and 3MB hard disk space.
      The retail price for the WinScheme Editor is $89.95.

   +  EdScheme for Windows v4.2a. This is an R4RS-compatible Windows-based
      Scheme interpreter. It is seamlessly integrated into the WinScheme
      Editor and provides a fully customizable transcript window that
      journals Scheme sessions and serves as a command window.  EdScheme
      can be customized by specifying a load-path, a start-up file of
      library procedures, and setting its level of Windows multi-tasking
      tolerance. EdScheme for Windows includes a turtle graphics 
      interface, Windows API access for creating windows, dialogs, and
      interacting with the mouse, and an integrated debugging facility.
      EdScheme for Windows is a 32-bit application that requires MS  
      Windows 3.1 or later (with Win32s), Windows 95 or Windows NT with 
      4MB RAM and 4MB of hard disk space.  The retail price for EdScheme 
      for Windows is $129.95. (Note: The WinScheme Editor is integrated 
      into EdScheme and does not need to be ordered separately.)

   +  3DScheme for Windows v1.3. This is a Windows-based R4RS Scheme
      interpreter incorporating over 550 geometrical Scheme primitives that
      access Spatial Technology Inc's ACIS (R) Geometric Modeling Kernel,
      the de facto industry standard in 3D modeling. The 3D modeling
      features include:
        -  construction of solid bodies from blocks, cylinders, cone
           frustums, spheres, and toruses.
        -  construction of wire-bodies from straight, circular,
           elliptical, Bezier, and spline edges.
        -  construction of solids by extruding planar faces or
           profiles along a vector or revolving about an axis.
        -  application of rigid transformations, uniform scaling, and
           boolean operations. 
        -  intersect, trim, fillet, and chain edges.
        -  simultaneous views of solids from several different angles.
        -  dynamically accepted event-driven input for picking,
           rubber banding, or dragging.
        -  rendering of solids using flat or Gouraud technology and
           configurable refinements, materials, texture spaces, and
           render lights. 
        -  saving and loading collections of solid and wire entities
           from disk in .sat format.
        -  outputting rendered images as high resolution bitmaps or
           Postscript files. 
      As with EdScheme for Windows, 3DScheme is seamlessly integrated with
      the WinScheme Editor.  3DScheme also ships with the "Getting Started
      with ACIS 3D Toolkit Using Scheme" book which is described below.  
      3DScheme is a 32-bit application that requires MS Windows 3.1 or 
      later (with Win32s), Windows 95 or Windows NT with 8MB RAM and 16MB 
      of hard disk space.  A 3DScheme demo program is available from the 
      Scheme repository in the "promo" directory or may be requested from 
      Schemers Inc. 3DScheme for Windows retails for $495 (call for academic 
      discount). (Note: The WinScheme Editor is integrated into 3DScheme and 
	does not need to be ordered separately.)

   +  EdScheme for Macintosh v4.0. This is an R4RS-compatible
      Macintosh-based Scheme interpreter.  The programming environment
      takes advantage of the capabilities of the Macintosh computer.  Its
      user interface includes a full-featured integrated editor, with
      special capabilities such as parenthesis-matching, program
      formatting, file indexing, and template editing.  In addition,
      customized transcript and debugging windows featuring colored and
      styled text are provided.  The interpreter features a powerful and
      comprehensive turtle graphics interface, unlimited precision "bignum"
      integral and rational/complex number arithmetic, file handling
      facilities, and language extensions using macros and transformers.
      EdScheme for Macintosh runs from floppy or hard drive and requires a
      Mac Plus or later, System 6.0.4 or better, and 2MB RAM.  EdScheme for
      Macintosh retails for $59.95.

   +  EdScheme for DOS v3.4. This is a DOS-based Scheme interpreter that
      incorporates a large subset of R4RS.  EdScheme for DOS features an
      integrated editor with automatic parenthesis-matching, a turtle
      graphics interface, debugging facility, comprehensive file-handling
      capabilities, macros and more.  It runs from floppy or hard drive and
      requires MS DOS 3.3 or later and 512KB RAM.  EdScheme for DOS retails
      for $49.95.

   + "The Schemer's Guide - Second Edition" by Iain Ferguson with 
     Edward Martin and Burt Kaufman.  Foreword by Daniel Friedman. 
     (1995--346pp.--Paper--ISBN 0-9628745-2-3)
     The Schemer's Guide presents the elements of modern computer programming 
     in an easy-to-follow and entertaining manner.  The book introduces 
     students to the Scheme programming language, guiding them through such 
     concepts as functional programming, recursion, data structures, higher 
     order functions, delayed evaluation, and object-oriented programming.  
     The Schemer's Guide concludes with a significant game-playing project
     involving artificial intelligence. The book strikes a good balance
     between theory and practice, while nurturing good programming
     practices.  The Schemer's Guide has a proven track record of several
     years use in teaching the art of Scheme programming to high school
     students and college undergraduates. A comprehensive teacher's guide
     and an additional set of resource materials including worksheets,
     quizzes, projects, and exams are available to instructors using this
     text.  The retail price of the book is $35.95. (A Spanish
     translation of "The Schemer's Guide" is available.)

   +  "The Schemer's Guide to C++" by Iain Ferguson
      (1996--92 pp.--Paper--ISBN 1-888579-11-0)
      The Schemer's Guide to C++ builds on the solid theoretical foundation
      provided by an increasing number of courses--such as those based on
      the introductory textbook, The Schemer's Guide--that introduce the
      principles of modern computer science via the Scheme language.  From
      this basis it provides students with a fundamental, pratical working
      knowledge of the programming language C++. The author uses his
      experience as a full-time, commercial programming professional to lead
      students step by step from the elegant principles of high level
      programming with which they are already familiar to the nitty-gritty
      of C++, but without ever losing sight of the computer science
      fundamentals that underlie good programming practice.  As in "The
      Schemer's Guide", students quickly learn to write complete,
      non-trivial programs, including the design and implementation of a
      modern container class library.  This unashamedly practical course is
      perfect for students and teachers who seek a clear, direct, fast-track
      path to learning C++.  The retail price of the book is $17.95.

   +  "Getting Started with ACIS 3D Toolkit Using Scheme" by Edward
      Martin.  (1995--260pp.--Paper--ISBN 0-9628745-1-5)
      This Getting Started book includes all you need to know about Scheme, 
      mathematics, and solid modeling to become a skilled 3D modeler using 
      3DScheme or the ACIS 3D Toolkit.  The retail price for the book is 
      $35.95, but is included free with 3DScheme for Windows.

   For more information about these products, write to Schemers Inc.,
   2136 NE 68th Street, Suite 401, Fort Lauderdale, FL 33308, call
   954-776-7376, or fax 954-776-6174. You can also send EMail to 

   Schemers' European distributor, Lambda Publications, is reachable by 
   phone at 44-793-695296 or by EMail on ···········

Gambit Scheme requires a license for commercial users. See the entry
in [2-1] for details.

Ibuki PC Scheme:

   Ibuki PC Scheme 5.01 is a modern, up-to-date implementation of TI
   PC-Scheme (see [2-1]). Ibuki purchased the rights to TI PC Scheme
   on July 13, 1992. Ibuki PC Scheme runs under DOS on all IBM
   compatible PCs, including 486s, and can use up to 4mb of extended
   memory. It will also run under Windows 3.1. For more information,
   contact IBUKI, 340 Second Street, PO Box 1627, Los Altos, CA 94022,
   phone (415) 961-4996, fax (415) 961-8016, email Richar Weyhrauch
   <···>. Ibuki has a special pricing program for schools
   teaching Scheme in courses. 


   MacScheme is a Scheme interpreter and compiler for the Apple Macintosh, and
   includes an editor, debugger and object system.  MacScheme costs $125
   (includes compiler) and Scheme Express costs $70 (interpreter only). It
   requires 1mb RAM. A development environment (MacScheme+Toolsmith) costs
   $495. Conforms to the Revised^4 Report on the Algorithmic Language Scheme.
   MacScheme+Toolsmith includes support for menus, windows, and interfaces to
   the Macintosh Toolbox, and can create small standalone Macintosh
   executables. Implemented by Will Clinger, John Ulrich, Liz Heller and Eric
   Ost.  Write to: Lightship Software, PO Box 1636, Beaverton, OR 97075, or
   call (503) 292-8765. They're moving to California. The temporary phone
   number is 415-940-4008 (Liz Heller). The new phone number will be
   415-694-7799, or fax bug reports to 415-694-7705 or 800-441-5015. 
   MacScheme is distributed by Academic Computing Specialists (ACS),
   2015 East 3300 South, Salt Lake City, UT 84109-2630, 1-800-531-3227
   or 1-800-552-1601 (801-484-3923), fax 801-467-2200. These products
   may also be purchased from Academic Computing Specialists, PO Box
   711, Dewey, AZ 86327, tel 602-632-7176, fax 602-632-7631.

Subject: [2-3] What Scheme-related discussion groups and mailing lists exist?
Before posting to any discussion group, please read the rest
of this FAQ, to make sure your question isn't already answered.

See the Lisp FAQ for a list of Lisp-related discussion groups and
mailing lists. We list here only those newsgroups and mailing lists
directly associated with Scheme.


   comp.lang.scheme        General Scheme-related discussion.
                           This newsgroup is available in digest
                           fromat as part of the Scheme Digest
   comp.lang.scheme.c      Discussion of C-Scheme, a scheme dialect
                           more commonly known as "MIT Scheme".
                           This newsgroup is gatewayed to the
                           ············ mailing list.
   comp.lang.scheme.scsh   Discussion of Scsh, the ``Scheme Shell'', a UNIX
			   shell/systems programming environment implemented
			   on top of Scheme 48 (a portable, byte-code
			   compiled R4RS Scheme implementation).
			   This newsgroup is gatewayed to the
			   ···· mailing list.
   comp.lang.lisp.x        Discussion of XLISP, a dialect of Lisp, and XScheme.
   comp.lang.dylan         Discussion of Dylan (see [4-6]), Apple's
                           new Scheme-like programming language. Gatewayed to

We list several mailing lists below. In general, to be added to
a mailing list, send mail to the "-request" version of the address.
This avoids flooding the mailing list with annoying and trivial
administrative requests. [To subscribe to info-mcl, info-dylan, or
other mailing lists based at, send a message to
········· with "subscribe <list_name>" in the
message body. Likewise use "unsubscribe <list_name>" to cancel your
subscription and "help" to get help.]

General Scheme Mailing Lists:

   ······           Discussion of Scheme. Gatewayed to
                                   the comp.lang.scheme newsgroup.
   ······               General discussion about Scheme.

Particular Flavors of Scheme:

   ············  C-Scheme. Gatewayed to the
                                   comp.lang.scheme.c newsgroup.

   ·········           T, a dialect of Scheme.

   ·············    PseudoScheme

   ··········  Dylan (not really scheme, but)

;;; *EOF*