LPmud

LPMUD refers to a family of text-based online multiplayer games that run on the LPMUD driver architecture and are programmed in the LPC language. The first LPMUDs were created by Lars Pensjö in the late 1980s and early 1990s, and the architecture rapidly became a popular platform for building persistent virtual worlds with user-created content.

Core to LPMUD is the separation of the server into a driver and a mudlib. The driver is the server process that handles network connections, scheduling, and persistence. The mudlib is a library of LPC objects that defines the game's rooms, monsters, items, and rules. Developers write new content by creating and inheriting objects in the mudlib; the inherited code allows reuse and extension without recompiling the driver.

Programming in LPC provides an object-oriented environment with features such as inheritance, dynamic function calls, and mappings and arrays. Rooms and NPCs are live objects, and player actions often invoke methods on these objects.

Over time, various drivers such as MudOS and FluffOS emerged to implement or improve the LPMUD architecture, enabling ports to modern operating systems and enhancing performance. LPMUDs flourished in the 1990s and remain in use in some communities, with a heritage that influenced other MUD designs that emphasize in-game object hierarchies and in-memory persistence.