Google Summer of Code 2012 project, GHCi for the web
The prototypes subdirectory contains several quick hacks demonstrating various concepts.
Using hint to download and execute code from the web
prototypes/scottywebexecute/ is examples/basic.hs from https://github.com/xich/scotty/ modified only slightly to prove to myself that I understand the code.
prototypes/hintdownloadexecute/ is the front end from http://haskell.handcraft.com/ modified to have scotty and hint as a backend instead of calling tryhaskell.org