[Haskell] Tools for web-based Haskell editing & compilation?

[Conal Elliott]

Has anyone set up GHC to run on a server with modules created, saved,
edited, imported, and executed via a web interface?  Are there tools
existing or under development that support some or all of this scenario?

I'm working on a new implementation, "Pajama", of the Pan functional
image synthesis DSEL, this time with the compiler targetting Java
applets.  (The image compiler is implemented in Haskell and generates
Java code.)  Besides running image effects, I'd also like to allow
people to author new effects without having any software installed (GHC,
the Pajama compiler, or the Java compiler).  For starters, I'm thinking
of an editor applet (running in a web page) and a compile server. 
Ideally, the editor would do syntax coloring and checking, show type
annotations, etc, though it doesn't have to do so initially.  When a
module compiles successfully, the user would select definitions that
would get run to generate Java code, which would then be compiled on the
server and downloaded to the client via an html applet tag.

Thanks,  - Conal