virtustan-mud
Virtustan MUD: the fork of Byliny MUD code (CircleMUD derivative) with Prool's own zones
Main repository of Virtustan MUD (aka Prool MUD) here: https://github.com/prool/virtustan-mud (since august'2019)
Installation instructions in Russian in file INSTALL.md
Site of Virtustan MUD (main language is Russian) - http://mud.kharkov.org
The Virtustan MUD: mud.kharkov.org, ports 3000 or 8888 (main MUD language is Russian, some English CircleMUD-style command allowed)
Prool