source: xincludes/texruntime.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" >


<para role="recommended">
  <xref role="runtime" linkend="python2"/> is used by the unmaintained
  ebong CTAN module (intended for writing Bengali in Rapid Roman Format).
  <filename>/usr/bin/python</filename> is also in the shebang line for the
  latex-papersize and lilyglyphs scripts, and documentation at CTAN says both
  modules have been updated to work with python3. In pythontex there are
  scripts to invoke python3 or python2 according to the system's version of
  <command>python</command>. <xref role="runtime" linkend="ruby"/> is used by
  two scripts, one is for pTex (Japanese vertical writing) and the other is
  match_parens which might be generally useful. The perl module <ulink
  url="https://cpan.metacpan.org/authors/id/S/SR/SREZIC/Tk-804.036.tar.gz">Tk</ulink>,
  which needs to be run from an X11 session to run the tests and
  requires <xref role="runtime" linkend="tk"/> is used by one of the scripts
  for ptex
  and is needed for texdoctk (a GUI interface for finding documentation files
  and opening them with the appropriate viewer).
  <command>ps2pdf</command>, from <xref role='runtime' linkend='gs'/>, is
  used by some utilities and scripts.
</para>