JXFire is a Multi-User Dungeon game written in Java. It is using the Sun Gaming Server (aka "Project Darkstar") framework. JXFire aims at testing various game mechanisms rarely used, like uncertainty in gaming data perception, self-organizing ecological systems, or non-instantaneous information propagation.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.