The Mercury MUD driver is a C++ network server for extensible text-based multi-user role playing games. Players can extend the game world on the fly (even while the game is running) via a simple object-oriented C-like language.

Although a bit retro in these days of MMORPG's and FPS's, MUDs and text-based adventure games still have a strong appeal to those who are more interested in role playing and using their imaginations, both as players and as game developers, than in eye candy and caffeine substitutes. ;)

The Mercury driver is primarily designed as a scripting and extension language for real-time interactive multi-user server applications. The canonical application is the Multi-User Domain, or MUD, where a native code driver provides the low level network and filesystem support and a scripting language is used to define and describe the "world".

From the req.games.mud.misc FAQ:

A MUD (Multiple User Dimension, Multiple User Dungeon, or Multiple User Dialogue) is a computer program which users can log into and explore. Each user takes control of a computerized persona/avatar/incarnation/character. You can walk around, chat with other characters, explore dangerous monster-infested areas, solve puzzles, and even create your very own rooms, descriptions and items.

Traditionally, the term MUD only applies to a text-based game, similiar in spirit to text based adventure games of bygone years.

Although written from scratch, Mercury is very similiar in concept to the LPMud driver (and its derivatives like Amylaar, MudOS, etc.) The Usenet group rec.games.mud.misc has a FAQ which goes into detail about all the different styles and implementations of MUD.

Okay, so why do "yet another MUD driver"? There are a couple of reasons:

• Although I'm a big fan of LPC and the LPMud drivers, they are definitely a bit dated, IMHO. Mercury's scripting language is intended to have a more modern look and feel, borrowing the best ideas from other languages like LPC, C++, Java, Perl and whatever else we feel like.
• Existing scripting/extension languages (like Perl, Python, etc.) either don't give me the kind of control over security and resource management that I want at the virtual machine level, don't have the features I want or are too obscure or non-mainstream to be useful.
• I want to play around with some ideas for multi-player interactive fiction, particularly non-player character AI and dynamic story lines (as opposed to a static "kill the ogre, get the key, unlock the box, solve the quest" type story telling.) To make it efficient and easy to use, a good deal of support may be required in the extension language and virtual machine themselves.
• As a pure computer science exercise, there is a certain attraction in developing a virtual machine, a high level language and compiler targetting it (leaving out the MUD application) I've been looking for an excuse to learn flex and bison for a while now, so here we are.