[Nakor]

Quote

The last few years have seen the rise of Web APIs - services exposed over plain HTTP rather than through a more formal service contract (like SOAP or WS*). Exposing services this way can make it easier to integrate functionality with a broad variety of device and client platforms, as well as create richer HTML experiences using Javascript from within the browser. Most large sites on the web now expose Web APIs (some examples: Facebook, Twitter, LinkedIn, Netflix, etc), and the usage of them is going to accelerate even more in the years ahead as connected devices proliferate and users demand richer user experiences.

Our new ASP.NET Web API support enables you to easily create powerful Web APIs that can be accessed from a broad range of clients (ranging from browsers using Javascript, to native apps on any mobile/client platform)

ASP.NET Web API

Nice overview of what the ASP.Net Web API is. I've played with it a little (very little) but it seems like a very easy way to quickly create an API for your application