TypeScript 0.9 introduces support for generics
Probably the most important update is the addition of generics, the feature most requested by TypeScript users, according to TypeScript program manager Jonathan Turner. Developers can use generics to introduce additional variables for types that are then switched out for concrete types when classes, interfaces or methods are used – this increases type safety when code is reused.
Microsoft has also reworked the compiler so that compiled results should now be closer to the language specification; performance when working with Microsoft's Visual Studio development environment also seems to have been improved. TypeScript 0.9 seems a bit slower than previous versions when working from the command line, but the language's developers plan to fix this issue in the next small update.
Other changes and updates can be found in Microsoft's release announcement. The source code for TypeScript 9.0 can be downloaded from the project's web site, which also includes installation instructions for installing the compiler with Node.js and NPM.