ErisMUD is a free MUD/MOO server and engine written from scratch in Python using SQLite for data storage. ErisMUD is distributed under the GPL. It is a work-in-progress but already has many features:

• Creating/destroying/listing rooms, items, NPCs with a single command.
• Moving around in all directions.
• Importing text maps directly into the system.
• ANSI colors.
• Basic health/damage system.
• Talking using the "say" command, chatting using the "chat" command.
• Cloning items, dropping them on the floor, getting them, giving them to other players.
• Instances: a single object may be cloned multiple times and every instance is independent.
• Easily add or modify help files with a single command.
• Logging.