From the website [1 ]:
Per the developer (Aug 2017 caius-users Google Group topic ), the Caius project is now only on limited maintenance.
ak - 2014-11-09 18:15:40
It is said to contain a pure Tcl package for processing Markdown.
dbohdan 2014-11-10: Indeed. See https://github.com/tobijk/caius/tree/master/lib/markdown .
APN The above now installs on Windows as well.