Microsoft’s open source language TypeScript is designed to make large-scale JavaScript application development easier while providing the benefits of modern tooling. The latest release candidate for the upcoming 1.0 release brings several changes to TypeScript since its previous 0.95 edition. Foremost among the changes is new handling of generics. The development team has changed the behavior of the “any” keyword. This has been done in an effort to simplify the type-checking performed when creating interfaces and subclasses.
This joins another change in how generic types are handled benefitting scenarios such as “fully-typed generic promise typings”. Another important addition is that the library lib.d.ts file bundled with TypeScript has been updated to provide touch and WebGL support.
While overall feedback to this release is positive, this is still a release candidate and it should not be installed on a critical production system unless you are willing to assume some risks. Some early adopters are indicating that there are still a few stability to bugs that need to be squashed.
Besides access via Update 2, TypeScript 1.0RC can also be downloaded and used as a standalone tool. The project’s full source code is maintained on Codeplex. Outside of Visual Studio, TypeScript enjoys support on Eclipse and Sublime among other popular text editors.