ROC Engine is a simple and lightweight 3Dgameengine. Keyframed skeletal animation with hardware skinning. Audio playback with spatialization (Ogg, WAV, FLAC). TrueType font rendering with Unicode characters support. All information about modeling and scripting is available at wiki. Check demo scene resources out for an example of engine usage.
CoffeeMud is a text-based virtual reality gameengine (a MUD). It is a mature, full-featured Java codebase. It includes web (HTTP) and email (SMTP) servers, chat (IMC2 and I3) and web clients, and supports ANSI, MXP, and MSP.
Crimild Engine is an open source scene graph based engine which purpose is to fulfil the high-performance requirements of typical multi-platform two and tridimensional multimedia projects, like games, simulations and virtual reality.
Framework and set of object-oriented and/or generic libraries designed for games and virtual reality simulations. Abstracts interfaces of APIs and provides additional general and high-level functionality for rapidly creating solid applications.
Cross-platform 3D Game Interpreter for 3D design games simulation and Virtual Reality Graphics Rendering with GUI and Command Line. Include map editor , game modeler , script editor.
MyWorld is an open virtual reality and gameengine. It is written and usable in C/C++. It has own abstract layers for Graphics and Physics. Actually we use Irrlicht for 3D-Rendering and GUI, and ODE for Physics. It is smart, powerful and easy to extend.
OpenReality will be a 3D Engine Library for development of Games, Virtual Reality and 3D Visualization applications. It will be very intuitive, and strongly object oriented. Of course, performance will have a great weight on the project´s decisions.
The VROnline project is universal 3D virtual reality engine for games with client/server architecture, free 3D camera, user configurable actions and AI scripts. It's based on C# and directX (now 9.0) technology. It can manage many data models(rpg,sims).