Macintosh

NetRPG
Small role playing game server with many MUDlike capabilities, which is also one of the only servers that is OpenTransport native.
http://www.bratton.com/egb/netrpg.html

SlashMUD
Modern Macintosh-hosted MUD server that features full support for classes, races, clans, ANSI color support, plain text data files, and automatic HTML generation, intelligent monsters,moods, and languages.
http://homepages.paradise.net.nz/koryn/