A mudlib, short for mud library, is a library of code forming part of the technical infrastructure of a MUD. Though different varieties of MUD may be considered to have mudlibs, the term is most often used with LPMuds. In an LPMud, the mudlib consists of interpreted code written in the LPC language, which is interpreted on the fly by a driver. The driver acts as a virtual machine while the mudlib acts as an operating system by defining how the world acts and controlling its processes.
Publicly available LPC mudlibs include:
- Bartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 43. ISBN 0-13-101816-7. "Above this layer is what (for historical reasons) is known as the mudlib58. [...] 58For "mud library". MUD1 had a mudlib, but it was an adaptation of the BCPL input/output library and therefore was at a lower level than today's mudlibs. The modern usage of the term was coined independently by LPMUD."
- Busey, Andrew (1995). Secrets of the MUD Wizards. SAMS Publishing. p. 239. ISBN 0-672-30723-5. "MUDLib is short for MUD library. [...] Files within a MUDLib are akin to books on the shelves of a library."
- Bartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 45. ISBN 0-13-101816-7. "Everything that is hard-coded constitutes the engine. For MUSHes and MOOs, the engine is just the driver; [...] for DikuMUDs it's the driver, the mudlib, and the world definition."
- Bartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 43. ISBN 0-13-101816-7. "The mudlib defines the physics of a virtual world, which will include things such as mass/weight, timers, movement and communication, along with higher concepts such as (in a game context) magic and combat mechanisms."