[NTG-pdftex] xpdf/poppler usage: Movements on the poppler side, and a request for help

Frank Küster frank at debian.org
Fri Oct 27 17:10:34 CEST 2006

Hans Hagen <pragma at wxs.nl> wrote:

> it makes more sense then to look into
> http://ccxvii.net/apparition/
> because "However, the poppler developers plan to make unavailable the
> old, undocumented, never planned and unmaintainable API of "plain
> libpoppler" is not something you want to repeat again

I am not the one to judge whether MuPDF or xpdf/poppler is the better
choice.  But I don't understand your argument about "is not something
you want to repeat again".  There never existed a clean API for xpdf,
people just used things they needed from different parts of the code.

poppler has forked xpdf to create a shared library, which is a move I
fully support.  poppler has built libraries with a well-defined,
reliable API on top of that, but has also provided the undefined "API"
that xpdf code-users are used to, and therefore poppler can currently be
used as a (nearly, one data type is renamed) drop-in replacement for

If the poppler developers now consider to no longer provide this
unreliable "API", but offer to create one more library with a
well-defined, reliable API for non-display uses - then I would say this
is something that speaks *for* poppler.  It seems to indicate that they
care for their users (and don't try to hide the problems with using an
undocumented API).

If it turns out that the poppler people are not willing to listen to
pdfTeX developers when it is about creating a non-display library
version: Then we can still decide that we should not switch to poppler
(or rather, for sure we will, since we don't want pdfTeX to be linked to
qt or gtk or such).

But I think we should not miss the opportunity to tell them our wishes.

> or alternatively, try to maintain a healthy relationship with Derek
> and stick to xpdf

I don't see why a healthy relationship with Derek is needed just to use
the code, but the point is that

a) there are valid reasons not to use the code as long as it can only be
   linked statically (note that at least Debian and Ubuntu Linux already
   link pdfTeX against libpoppler for those reasons)

b) people who have tried to maintain or build up a relationship to Derek
   have not been able to convince him to provide a shared library.

So while I have nothing against MuPDF, I still think some pdfTeX
developer should get in touch with the poppler peopler and communicate
with them.  They have asked, and after all I expect that it will be much
easier to switch to a poppler library that has been taylored along our
wishes, than to MuPDF which exists independently and doesn't seem to
have any relationship to the xpdf code we currently use.

Regards, Frank

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

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