Ralph Churchill is developing Chuchomud. He's using the network parts of TeensyMud.

Reyn Vlietstra is developing ruby-mud home or ruby-mud sourceforge.

Michael Granger and others are working on MUES which stands for Multi-user Environmental Server.

Michael Manlief and others are writing Rbmud.

Travis Smith is working on Muddy Gems MUD Driver.

Bob Aman is planning Mudclay.

James Costlow is developing Multi-User Unified Network MUUN.