[tex-live] Unclear License of AMSLaTeX

Frank Küster frank at kuesterei.ch
Fri Apr 28 20:26:59 CEST 2006

karl at freefriends.org (Karl Berry) wrote:

>     - it does not permit to distribute changed versions, even when renamed,
> Well, once you have a changed version, further copying of that unchanged
> version could perhaps be construed as permitted under clause (1).

Further copying for your private use, yes.  But in IP law, everything
that isn't explictly allowed is generally forbidden.  Therefore I must
correct me:  This doesn't allow anyone to distribute amslatex, not even
unchanged versions; only AMS is allowed to do so.

>     - this text doesn't even allow to copy amsclass.dtx to amsclass.dtx.bak
> Hmm.  Perhaps the name change could be interpreted as part of "if you do
> make changes", ie, one possible change is changing the name.  Imagine
> cp amsclass.dtx{,.bak}, changing one byte, then reverting the one byte ...

Well, one could read it this way.  

> I am straining to find a way to interpret the clauses non-literally
> because I agree with you that the wording here is not ideal.  However,
> amslatex is not the only issue.  plain.tex and other basic TeX system
> files written by DEK (and others) are under a similar license.
> Furthermore, tex.web and mf.web are under an even more "restrictive"
> license.

No, Knuth's stuff is not a problem I think.  At least for tex.web and
mf.web I am sure.  Look at http://www.ntg.nl/maps/pdf/5_34.pdf

Here Knuth essentially says that the code is public domain, and only
imposes restrictions on naming:

   | My work on developing TEX, METAFONT, and Computer
   | Modern has come to an end. I willmake no further
   | changes except to correct extremely serious bugs.
   | I have put these systems into the public domain so that
   | people everywhere can use the ideas freely if they wish.
   | [...]
   | As stated on the copyright pages of Volumes B, D, and
   | E, anybody can make use of my programs in whatever
   | way they wish, as long as they do not use the names
   | TEX, METAFONT, or Computer Modern. In particular,
   | any person or group who wants to produce a program
   | superior to mine is free to do so. However, nobody is
   | allowed to call a system TEX or METAFONT unless that
   | system conforms 100% to my own programs, as I have
   | specified in the manuals for the TRIP and TRAP tests.
   | And nobody is allowed to use the names of the Computer
   | Modern fonts in Volume E for any fonts that do not
   | produce identical tfm files. This prohibition applies to
   | all people or machines, whether appointed by TUG or
   | by any other organization. I do not intend to delegate the
   | responsibility formaintainance of TEX, METAFONT, or
   | Computer Modern to anybody else, ever.

Therefore, pdfTeX 1.40 has been promised to to not use tex.web at all,
but only its already changed version.

> I do not believe it is in the overall public interest to ask DEK to
> spend one second contemplating these things instead of working on the
> Art of Computer Programming.  I am also virtually certain (barbara might
> chime in) that it would be a waste of time, as he has made his wishes
> clear many, many times and would not be inclined to change anything.
> The fact that a literal interpretation of his "license" texts is not
> perfectly congruent with his wishes is an unfortunate fact of life.

I think the text quoted above makes his wishes quite literal, and IMO
are perfectly free by any sane or debianish ;-) criterion.

Regards, Frank
Frank Küster
Single Molecule Spectroscopy, Protein Folding @ Inst. f. Biochemie, Univ. Zürich
Debian Developer (teTeX)

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