Description.md

ReSharper thinks this type is unused because it isn't referenced anywhere, but it's actually being picked up by convention. There's also several other ways this class can be used.

You can read more about the OWIN Startup Class Detection here.

Startup.cs

using Owin;
using JetBrains.Annotations;

namespace MyAwesomeApp
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
            app.UseNancy();
        }
    }
}

Here's the code for the new (ASP.NET vNext) startup loader: https://github.com/aspnet/Hosting/blob/dev/src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs

And the code for the current (Katana) startup loader: http://katanaproject.codeplex.com/SourceControl/latest#src/Owin.Loader/DefaultLoader.cs