F#, Owin, ASP.NET Identity, SignalR... It can be used as a back-end server for a single-page application (SPA), exposing only OAuth and Web Sockets endpoints, and it is supposed to be paired with a web application front-end (.html, .css, .js, images) hosted in CDN and developed in a seporate project. This project can be mixed with other server-side technologies like Nancy, F# SQL Command Provider etc.