In this chapter, we will concentrate on the ASP.NET platform. At the time of writing this book, ASP.NET 5 was not released. However, the OWIN project existed, and the code looked almost the same as in ASP.NET 5. So this was used to write the sample server applications. When ASP.NET 5 will be released, it will be easy to convert this code to the new platform. We will not go into the details of OWIN; it is an acronym for Open Web Interface for .NET, and basically, it is a way to compose application components with each other. It is a part of the ASP.NET ecosystem, and all we need to know for now is that with OWIN we can write HTTP services.

When we use ASP.NET, we see a typical HTTP application platform. First, there is an HTTP host that accepts incoming connections from clients. It can be a full Internet Information Services web server, or it can be a simple HTTP listener hosted in a usual .NET process. After the incoming HTTP request is processed by the HTTP host...