TypeScript is a programming language that makes it easier to write cross-platform, application scale, JavaScript that runs in any browser or in any host. Microsoft Technical Fellow Anders Hejlsberg explains how TypeScript, which is a typed superset of JavaScript that compiles to idiomatic (normal) JavaScript, can dramatically improve your productivity by enabling rich tooling experiences, all while maintaining your existing code and continuing to use the same JavaScript libraries you already love.

The TypeScript language specification is available under Open Web Foundation and the compiler implementation is available as Open Source.