Recently, I have been using OWIN a good deal for developing internal web applications. One of the chief benefits of this is that OWIN offers the ability to host its own HTTP server, which allows me to get out of the business of installing and configuring IIS on windows, which is one of the main points of pain when deploying the products I work on to our customers. Unfortunately, when I first started using OWIN, there was not a version of ASP.NET MVC available that was compatible with OWIN. Most of my previous experience with programming web servers has been based on MVC (except for briefly experiencing WebForms hell), so finding a similar framework that was compatible with OWIN was one of my first priorities.
In my search, I discovered Nancy, a fairly similar MVC-style framework which offered OWIN support. It also was capable of using the same Razor view engine as ASP.NET MVC, with some minor differences, so I was able to convert existing IIS ASP.NET MVC applications to OWIN/Nancy using most of the existing views and front-end code. At some point I plan to write an article illustrating how one would do this type of conversion, but for now, I'm going to examine one particular gotcha I discovered when converting my personal Netflix-type video application to OWIN/Nancy: serving HTML5 video files.