ASP.NET 5 Kestrel Web Server

ASP.NET 5 - A Deep Dive into the ASP.NET 5 Runtime

"ASP.NET 5 comes with built-in support for running on IIS (Microsoft.AspNet.Server.IIS), directly on a thin HTTP.SYS wrapper (Microsoft.AspNet.Server.Web­Listener), and on a new .NET cross-platform Web server called Kestrel (Microsoft.AspNet.Server.Kestrel).

...

The Katana Project (katanaproject.codeplex.com) was Microsoft’s initial effort to implement support for OWIN, and many of the ideas and concepts in ASP.NET 5 were derived from it. Katana had a similar model for building up a middleware pipeline and for hosting on multiple servers. However, unlike Katana, which exposed the low-level OWIN abstractions directly to the developer, ASP.NET 5 instead bridges from OWIN to more convenient and user-friendly abstractions. With a little extra code you can still use Katana middleware in ASP.NET 5 using the OWIN bridge"

NuGet Gallery | Microsoft.AspNet.Server.Kestrel 1.0.0-rc1-final

aspnet/KestrelHttpServer · GitHub
"a web server for ASP.NET 5 based on libuv.
This project is part of ASP.NET 5"

libuv/libuv · GitHub

libuv is a multi-platform support library with a focus on asynchronous I/O. It was primarily developed for use by Node.js, but it's also used by Luvit, Julia, pyuv, and others.