You can now generate TypeScript definition (*.d.ts) files from either .Net or .winmd assembly files. Allowing you to leverage these libraries in your TypeScript/JavaScript WinJS or other client side software applications with all the type safety and benefits of TypeScript.

I know of two main scenarios where I think this could be useful.

1. If you build a 'Modern' (come on, we still call it Metro) Windows 8 app with WinJS and want to leverage TypeScript, wouldn't it be nice to get a set of TypeScript Definition files that reflect the native API's you're calling in the platform without manually creating the definition files?
2. Say your building an MVC/WebAPI server application. It would be useful if your C.I./Build system could spit out a set of TypeScript interfaces that were based on the server objects used to render your API. This can provide not only useful for client side JavaScript/TypeScript libraries that need to consume these objects, but could also provide a simple way to document the structure of your service API results.

Install via Chocolatey

cinst ToTypeScriptD

You can see the Chocolatey package here: ToTypeScriptD package

ToTypeScript --help

ToTypeScriptD winmd "C:\Program Files (x86)\Windows Kits\8.0\References\CommonConfiguration\Neutral\Windows.winmd"

ToTypeScriptD winmd C:\Windows\System32\WinMetadata\Windows.Foundation.winmd C:\Windows\System32\WinMetadata\Windows.Networking.winmd

ToTypeScriptD winmd --specialTypes C:\Windows\System32\WinMetadata\Windows.Foundation.winmd

ToTypeScriptD winmd --specialTypes C:\Windows\System32\WinMetadata\Windows.Foundation.winmd --regexFilter "Windows.Foundation.Collections"

Checkout the project milestones, suggest a feature, bug etc. Or even better, submit a pull request.

Checkout the Contribution guide.

Partially sponsored by:

By loading assembly metadata with Mono.Cecil which can read any Ecma 355 Common Language Infrastructure (CLI) file, we can generate a set of TypeScript definition files that allow us to project the type system from these assemblies into TypeScript Definition files. Cool eh?