is used by the unmaintained ebong CTAN module (intended for writing Bengali in Rapid Roman Format). /usr/bin/python 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 python. 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 Tk, which needs to be run from an X11 session to run the tests and requires 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). ps2pdf, from , is used by some utilities and scripts.