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From: rokicki@rocky.UUCP
Newsgroups: comp.sources.d,misc.legal,comp.sys.atari.st
Subject: Re: Copyright status of Ctex and Common-Tex: whose copyright ???
Message-ID: <626@rocky.STANFORD.EDU>
Date: Wed, 30-Sep-87 11:47:33 EDT
Article-I.D.: rocky.626
Posted: Wed Sep 30 11:47:33 1987
Date-Received: Sat, 3-Oct-87 06:24:09 EDT
References: <167@yetti.UUCP> <4760@ncoast.UUCP> <15392@amdahl.amdahl.com>
Reply-To: rokicki@rocky.UUCP (Tomas Rokicki)
Organization: Stanford University Computer Science Department
Lines: 43
Xref: utgpu comp.sources.d:1226 misc.legal:2185 comp.sys.atari.st:5055

> % This program is copyright (C) 1982 by D. E. Knuth; all rights are reserved
> % Copying of this file is authorized only if (1) you are D. E. Knuth, or if
> % (2) you make absolutely no changes to your copy. (The WEB system provides
> % for alterations via an auxiliary file; the master file should stay intact.
>
> How do they expect to enforce the 'no changes' section of this copyright?
> Are they going to checksum each version that they find?  Are they going
> to drag someone into court because their Pascal compiler makes an altered 
> copy of TeX by rewriting it in assembler?  Do they really think that someone
> won't edit the source to get it to compile on their compiler?

Please, give Don a bit more credit than that.  First of all, the Pascal
compiler's transformation into assembly creates a file which is not a
copy of the original, and it is also a necessary step to get the program
to work on a machine.  Secondly, as the message above states, the WEB
system allows you to make any necessary changes in a small auxillary
file.  The WEB system's macro processor allows global changes to be
stated once, and the program is written so as to isolate those system
dependent changes.  This also allows you to update your version of TeX
simply by getting the new master copy and using the same auxillary file
with your local changes.

And, no, nobody is going to checksum each version they find.  Rather,
no one may distribute a version of TeX that does not fit the
following three criteria:

	1.  It must pass a standard validation suite called
		`trip', with identical results to the master
		copy.  This test suite exercises all of the
		lines in the code except a few seriously
		fatal error messages, including the limitations
		of the program.
	2.  It work reasonably well and identicallly on
		`normal' documents (which trip certainly is
		not.)
	3.  The implementer must be happy with his
		implementation.

	Only (1) and (2) of the above can be tested, but if a
version is found that violates either of these, and is called
TeX, its distribution will be stopped.

						-tom