[luffy]

First off, I love F#. I use it extensively for offline data processing, managing our build process (via FAKE), and general purpose Windows scripting. I've also dabbled in DSL creation, and if you follow any of examples it really is pretty easy to do. As Don Syme (F#'s creator) has said, F# is a lot like a statically typed Python (with lots more syntax).

But I wouldn't use it with ASP.NET. Learning F# is pretty heady and it would give your average .NET developer fits to learn it. You'd lose an advantage of using the .NET platform then - it's pretty easy to get average developers to be productive in .NET/C#. Forcing developers to learn F# would grind productivity to a halt.

Also, because of the whitespace requirements, F# is lousy in the webforms view engine. (Perhaps a Mako-like templating engine for F# would make sense).

Stick with C# for your web work and your libraries that your web site are using. Life will be easier.

If you really want to delve into F# on the web, these guys did a framework designed to be used with F#: http://www.bistroframework.org/

They also did a .NET port of the django templating engine: http://ndjango.org/

[MichaelGG]

Most of the time, we use F# on the backend, using C# as little as possible. For web apps, that usually means the ASPX files themselves. For the MVC controllers, writing them in F# seems to work great.

The largest contention point arises when we pass F#-ish types to the ASPX page for rendering. It works, it's just that the C# required at that point can be sort of ugly.

Also, don't forget WebSharper, which provides a way to write all your client-side code (JavaScript) in F#. It handles all sorts of things, including async RPC calls. http://www.intellifactory.com/products/wsp/Home.aspx

[luffy]

The Intellifactory guys really know their F#. But this seems too much like WebForms and MSAjax for my tastes. After a while autogenerated javascript and HTML becomes very problematic, to say the least. If I want javascript, I'll just write it myself.

Now what I'd really like to see is an F# stand alone webserver - that would operate outside of ASP.NET/IIS. I envision a functional Request/Response pipeline, where you can augment the pipeline using function compositoin. Perhaps this could even handled by a computation expression or workflow. ( For those unfamiliar with F#, this is one of the killer features. See how simple it is to handle Async or parallel processing in F#).

Chris Smith has an interesting example of a Session State workflow in his F# book - I would like to see someone attempt that with a full fledged server.