Idioms!
Social coding website. Problems navigable through graph visualization (done with the javascript infovis toolkit) mapped to Backbone models with Rails/Postgres back-end.
Browse problems, submit solutions, create new problems, or just zoom around the tree.
(hard to discover feature - try clicking on the title of any problem when viewing your completed problems on your profile page. It'll pop you back into the graph view and zoom your view to center on the appropriate problem)
To-do
- Add solution graphs
- Add support for javascript
- Add a Ruby REPL