CoffeeMud is a text-based virtual reality game engine (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.
Crazy Eddie's GUI (CEGUI) system is a graphical userinterface C++ library. It was designed particularly for the needs of videogames, but the library is usable for non-game tasks, such as any other type of applications (rendering/visualisation/virtual reality) and tools. It is designed for user flexibility in look-and-feel, as well as being adaptable to the user's choice in tools and operating systems.
VRT is a Virtual Reality Toolkit.
It is planned to be OS-independent, easy-to-use, full-feature VR platform.
It integrates 3D engine, physical engine and AI engine.