[Indic-dev] GPL fonts

Radhakrishnan CV indic-dev@tug.org
Mon, 4 Nov 2002 12:53:35 +0530 (IST)

TUGIndia face a problem now consequent to the donation of a type1
Malayalam font, Keli by Hashim, which is to be released under a
copyleft licence. Also another font development team has agreed to
release their beautiful set of type1 fonts called 'rachana' under
any copyleft licence that we think appropriate and is with us now.

We have a very tricky problem to tackle as a consequence of the
above. We thought of releasing all the fonts under GNU GPL, but
there is a problem that I will list out below.

Unlike other typesetting applications, TeX or pdfTeX is a compiler
for a language called TeX, the TeX document we create is the source
code for the compiler and the compiled output is a PDF which unlike
other binary outputs of normal language compilers, is a printable
and viewable document. That is the only difference between normal
compilers and TeX compiler.

Suppose the government wants to release the statistic of citizens
with genetic disorders. This can easily be generated with TeXDBI, a
LaTeX package recently released under a copyleft licence during
TUG2002, which helps to generate a report from any RDBMS with
pdfTeX. pdfTeX then accesses the database making use of functions
defined in the TeXDBI package dynamically and generates a PDF
output. The actual TeX sources for this to happen is a very sleek
code of a few lines wherein TeXDBI calls are properly coded.

Now imagine that Keli font which is released under GPL (so far we
haven't done it for want of clarification on the doubts raised now,
this supposition is for the sake of this discussion) is used to
typeset the document, which means the pdfTeX compiler uses the font
which in turn keeps all the glyph information and font metrics in
the PDF document. In short, the font acts as a library in the normal
parlance of program sources and compilation. In effect, this forces
the author to release the source TeX code along with the output.

Although this is in no way a problem to release the TeX sources,
there is a catch in it that the TeX sources are useless without dump
of the database or a permission to access the data server, which
means the government is inclined to release the dump of the database
to the public. This leads to breach of privacy of its citizens,
since anyone can know the sensitive information of any citizen which
she would never want to share with others.

In this connection here are my doubts:

1. Is my assumption that font in a TeX document acts as a library
   correct? If not, will it be tenable in a court of law if it is
   brought to litigation?

2. How does the source of a compiled output defined? Does it mean that
   it should generate the exact output as the author's output?  If
   not, what are all the allowances/constraints on the end user?

3. Supposing that LaTeX packages used to compile a TeX sources are
   released under GNU GPL, does it cast upon the author of a TeX
   output as in the case described above to release the database which
   may contain national security information to the public?

4. It should be noted that PDF output of a TeX compilation can be an
   application also instead of a dumb document as popularly believed.
   Hans Hagen of Pragma ADE, Netherlands has created a PDF document
   namely calculat.pdf, using pdfTeX and a TeX sources he wrote which
   is a fully functional scientific calculator. See:

I have forwarded this mail to FSF India's Board for their opinion, 
but yet to hear from them. In the meantime, I would invite the 
comments from you all.