[citation needed] OWIN aims to decouple the relationship between ASP.NET [1][2]applications and IIS by defining a standard interface.
Project Katana is a set of OWIN components for ASP.NET (.NET Framework) built by Microsoft.
[citation needed] ASP.NET Core (.NET) has its own middleware system that is similar to OWIN.
In Project Katana, Microsoft has made into OWIN modules several ASP.NET features that were previously part of the core ASP.NET framework.
[6] This allows them to be reused in other Web frameworks, and also ensures a cleaner separation from the application using them.