Microsoft is making the new language open-source under the Open Web Foundation’s Final Specification Agreement (OWFa 1.0). Microsoft’s implementation of the compiler is also available on CodePlex (with git) under the Apache 2.0 license. Over the next few months, the TypeScript team will continue to develop CodePlex in the open.
Somasegar says the new language is an early preview, and invites the community give it a test drive. That said, developers can learn more about the TypeScript project here, download an early preview, read and discuss the language specification, explore the online playground, and peruse the source of the compiler (on the TypeScript project site on CodePlex, with git).
A 53-minute video overview can be watched here.