This add-on is part of YstokHTML and based on code proposed by Timofei Shatrov. It converts pseudo-tags and other patterns used in forums into HTML:
This add-on internally relies on regular expressions search. Within YstokHTML, handling Emacs-like expressions is implemented by LispWorks and interfaced by Ystok-Library.
But this add-on can also be used outside YstokHTML provided YHTML-Template and Edi Weitz's CL-PPCRE are loaded.