Is it possible to write a simple custom Console Application that includes a owin library that can host a Asp.Net Web Application directly (without katana.exe, like CassiniDev's library)? Is it possible to let an Asp.Net Web Application including MVC 4, Web API, SignalR features hosted across IIS and owin, without / rarely changing code?
For hosting applications from the ASP .NET framework family on top of OWIN, as of this post, you can do so with WebAPI and SignalR. If you need something more like MVC and Razor, you can look at using the NancyFX web app framework for that. Maybe in future versions of MVC OWIN support will be enabled