Aside from having access to all the Java web frameworks, Clojure has Compojure and Conjure on the higher level and Ring (equivalent to Python's WSGI and Ruby's Rack) for lower level.
I wouldn't discount Clojure as not ready for complicated web applications based on it's young age; Java servlets can be written in Clojure. Not that Java servlets are great, but they are widely used for non-trivial web sites.
Clojure is great at removing the ugliness of some Java APIs, I recall that Compojure is built atop servlets.
Re:A Rails like framework for Clojure.
by weavejester on Monday September 14, 2009 @04:46PM
(#822580)
Compojure is built on top of Ring, but can wrap a Ring "handler" function in a Java servlet.
This functionality has been merged into Ring 0.1, so you may now be able to wrap a Conjure application into a Java servlet as well.
It can be used to publish simple websites pretty elegantly, but for now it is relatively "low level"- I would say it still has a ways to go before being "Rails like."