A MUSH (acronym for Multi-User Shared Hallucination) is a type of MUD which is often used for social and role-playing activities. It is derived from "Tinymud", an early mud server. Its distinguishing features are that any player can typically extend the virtual world by building new rooms and objects, and its internal programming language, MUSHcode, which is considered to be fairly easy to learn and preferred by many.
There are a number of flavors of MUSH server freely available to those who want to run their own MUSHes: TinyMUSH 3.0, TinyMUX 2.4, and PennMUSH 1.8.x. TinyMUSH uses a disk-based database, while PennMUSH keeps its database in the computer's memory (TinyMUX can do either). This makes PennMUSH suitable for computers which have plenty of memory or little disk space. From a user standpoint they offer many similar features and a very similar command parser.
 Types of MUSH Servers
There are four major MUSH code bases currently in use:
- TinyMUSH - TinyMUSH 3.x is based on a merge of TinyMUSH 2.2 and TinyMUX 1.x. TinyMUSH 2.2 is based on TinyMUSH 2.0 which is based on TinyCRWU and PernMUSH (the code) which are in turn based on MicroMUSE, TinyMUSH 1.0, and ultimately from TinyMUD.
- PennMUSH - PennMUSH derives from PernMUSH (the code), MicroMUSE, TinyMUSH 1.0 and ultimately from TinyMUD.
- TinyMUX - TinyMUX 2.0 is based on TinyMUX 1.x which in turn is based on TinyMUSH 2.0 and ultimately TinyMUD.
- RhostMUSH - RhostMUSH 3.9 is based on the RhostMUSH 3.2.4 which is based on RhostMUSH 2.0/1.0 and ultimately TinyMUD.
- M*U*S*H - The live sandbox for projects on the PennMUSH code base and also the official MUSH used as the testing ground for new PennMUSH server code updates. All patches are tested there first before being released to the public. This is primarily an OOC MUSH.
- Shangrila - Adult-oriented MUX, attaining anywhere from over 200 to almost 600 connections.
- Beast Wars Transformers MUSH
- Loneport MUSH
- My Little Pony MUSH
- Pokémorph MUSH
- Starfox MUSH
- Thunder Trails MUSH
- Wild Spirits MUSH
 See Also
|Text-based multiplayer worlds|
Oldest still running