LPMud is a MUD variant developed in 1989 by Lars Pensjö that separates the mud game functionality between a virtual machine known as the driver and world-building components in the LPC programming language.

Lars had been an avid player of TinyMUD and Abermud. He wanted to create a world with the flexibility of TinyMUD and the power of Abermud, Furthermore, he did not want to have sole responsibility for creating and maintaining the game world. He once said, "I didn't think I would be able to design a good adventure. By allowing wizards coding rights, I thought others could help me with this." The result was the creation of a new, C-based, object-oriented programming language that made it simple for people with minimal programming skills to add elements like rooms, weapons, and monsters to a gaming world.

To accomplish his goal, Lars wrote what today would be called a virtual machine, the LPMud driver. The driver managed the interpretation of LPC code as well as providing basic operating system services to the LPC code. By virtue of this design, Lars ensured that poor programming of infinite loops, memory leaks, and other common programmer foibles by game builders would not harm the overall stability of the game. His choice of an OO approach made it easy for new programmers to concentrate on the task of "building a room" rather than programming logic.

By the end of 1989, there were two major muds built on top of the LPMud engine:

• Genesis LPMud (Lars' original LPMud)
• Nanvaent

Lars interest in LPMuds eventually waned. By the time it did, however, LPMud had become one of the most popular forms of mud. His work has been extended or reverse engineered in the following drivers:

• CD (short for Chalmers Datenforung, the computer club of the Chalmers University of Technology)
• Amylaar (also known as LPMud 3.x)
• MudOS
• DGD (Dworkin's Generic Driver)

The LPMud approach also enabled the development of gaming frameworks built in LPC that game builders could use as the foundation for their worlds. The original mudlib was the Genesis Mudlib that came with LPMud drivers up to LPMud 2.4.5. As LPMud matured, the separation between driver and mudlib grew to the point that the developers of MudOS and DGD did not ship their drivers with fully functional mudlibs. Popular LPMud mudlibs include:

• Genesis Mudlib from Genesis LPMud
• CD lib from Genesis LPMud
• Discworld Mudlib from Discworld MUD
• Nightmare Mudlib from Nightmare LPMud
• TMI Mudlib from The Mud Institute
• Lima Mudlib from Lima Bean

• LPMud FAQ
• LPMud Timeline