See http://mruckert.userweb.mwn.de/hint/web2w.html UTF-8 changes can be seen as follows: make -C web2w diff -u web2w/tex.w tex.w (if you need a new mapping, regenerate tex.w using these changes on web2w/tex.w, obtained using the new mapping) Recent version of glibc must be used (otherwise you may get "Segmentation fault" errors). It is assumed that this repo is in /home/user/. For MetaPost add 'TEX = tex' to texmf.cnf To use debugger, run "gdb plain" To run TeX, use "exec /home/user/tex/plain"