A good alternative to GWT for Clojure
GWT is used in the real world!!! A lot! And google is doing some pretty huge things with it so I don't think popularity is a valid concern.
I don't want to start a flame war so I won't elaborate any more on this.
Also, remember that GWT is a java - javascript compiler. No bytecode will run on the client. Hence, you can only use java, not clojure code when writing client-side code.