Union 1.0 is now shipping and ready for production use in real-world deployments.
Union is a development platform for creating multiuser applications. Build chat, whiteboards, real-time multiplayer games, meeting applications, collaborative editing tools, and shared interfaces that run in desktop and mobile web browsers (JavaScript), Adobe Flash, Java, C#, or dozens of other languages.
To get started building your own multiuser Union applications, follow the Union Quick Start guide.
There's lots more information, documentation, and examples at www.unionplatform.com.