Tl;dr: You can use NTLM authentication without relying on IIS or HttpListener in OWIN projects by using my OWIN autentication middleware: more information on my Github project: Pysco68.Owin.Authentication.Ntlm middleware. It’s working flawlessly with ASP.NET Identity 2.0! And there’s a Nuget package too!
As you may have noticed, I’m relatively busy these days with things like OWIN and surrounding technologies. All there shiny and new things that just fit together so well. And then you have customers just requiring plain old things like NTLM for their latest shiny intranet application.