"The OpenSource Metaverse Project was created because a strong demand exists, and large developer following, for virtual worlds that allow customization by the player and creation of one's own worlds. Closed source virtual worlds exist already - Second Life, There and Active Worlds - but we needed a metaverse engine that is flexible, scalable and that we can customize to an extent not possible within individual proprietary worlds."
Weave (BETA 1.0) is a new web-based visualization platform designed to enable visualization of any available data by anyone for any purpose. Weave is an application development platform supporting multiple levels of user proficiency - novice to advanced - as well as the ability to integrate, disseminate and visualize data at "nested" levels of geography.
Miso is an open source toolkit designed to expedite the creation of high-quality interactive storytelling and data visualisation content. The first release under the Miso Project is Dataset, a JavaScript client-side data management and transformation library.
Cytoscape is an open source software platform for visualizing complex-networks and integrating these with any type of attribute data. A lot of plugins are available for various kinds of problem domains, including bioinformatics, social network analysis, and semantic web.