Are OWIN and Katana the Microsoft projects you’ve never heard of? OWIN defines an open standard interface between .NET web servers and web applications.
So what does that mean? It means decoupling .NET web development from the server we always had to use: IIS. There are good use cases to host web frameworks in something other than IIS, such as your own application, and OWIN enables portability of your work. It can run in IIS… or it can run anywhere you need it.