From: Tayssir John Gabbour
Subject: Re: meaning of a dialet or implementation of a programming language
Date: 
Message-ID: <chvknq$129@odah37.prod.google.com>
Matt wrote:
> I always heard dialet of programming language. For example, Common
> Lisp is a dialet of Lisp programming language. What does it really
> mean? Lisp is not standardize yet? why there are dialets? Or when
> people say implementation of a programming language.
>
> please advise. thanks!!

The word is actually "dialect," and here's a good definition to start
out with.
http://dictionary.reference.com/search?q=dialect&r=67

A paper on the evolution of lisp:
http://www.dreamsongs.com/NewFiles/HOPL2-Uncut.pdf