Subject: Re: Document formats (was: To the keepers of the holy grail of Open Source)
From: Ian Lance Taylor <ian@airs.com>
Date: 23 Jan 2001 11:52:11 -0800

Rick Moen <rick@linuxmafia.com> writes:

> LaTex is "based on" Knuth's work in the sense that it implements the TeX
> design, but my understanding is that it is not a derivative work in a
> copyright sense, but rather was written separately by Leslie Lamport,
> and is now maintained by the LaTeX3 Project
> (http://www.latex-project.org/latex3.html).

TeX is essentially a programming language interpreter.  The language
it interprets might be called the TeX language.

LaTeX is essentially a library written in the TeX language.  Arguably,
LaTeX is only a derived work in the sense that a program which runs on
the Linux kernel is a derived work.

(If you don't use LaTeX, you typically use a different library written
by Knuth, known as Plain TeX.)

Ian