The Interreality project is a collection of Open Source, Free Software projects based on the Virtual Object System (VOS) platform. The goal is to develop a free and open platform for multi-user 3D virtual reality games, applications, and interactive, collaborative 3D virtual spaces. VOS is a powerful and generic network object framework designed to support a variety of high-performance applications. It is the basis for Ter'Angreal, a general-purpose browser application for entering and participating in 3D worlds.
Deliantra is an advancement of the crossfire multi-user RPG game. Unlike the original project, it focuses mainly on stability and playability, but also adds modern technology such as map scripting, Perl server extensions, asynchronous I/O, higher resolution graphics, and better client support.
The Second Life Viewer is the client for logging into the Second Life 3-D virtual world, where residents explore, purchase virtual land, open businesses, build real estate, and create scripted objects such as cars, robots, or magic wands. Second Life residents retain full intellectual property rights for the digital content they create and upload, including avatar characters, clothing, scripts, textures, objects, and designs.