This is a simple question: what are the most popular/used/developed (libraries a plus) functional programming languages that are ready to be used for web development? I don\'t
This answer is partly in jest, but some people try their best to do functional programming in JavaScript:
http://osteele.com/sources/javascript/functional/
Javascript as a functional language
Using the same language on client and server has to count as a plus, even if the language isn't purely functional.
I have not used it myself, but WebSharper looks interesting.
Haskell has a plethora of web frameworks. The most well-established framework is Happs, but there are several new and active projects:
The full list is on the Haskell wiki.
OCaml has a web framework, Ocsigen
The language also comes with some nifty utilities that makes easy to build simple web applications, like netplex module (I've used it before in a school project, an mvc framework, it did almost all the web/socket part)
You might want to take a look at Erlang's Webmachine, MochiWeb (includes a bunch of libraries), Nitrogen, etc.
http://bitbucket.org/justin/webmachine/wiki/Home
http://github.com/mochi/mochiweb
http://nitrogenproject.com/
These are the few I could remember top of my head: