Great questions guys - we use locked-down language sandboxes on our own servers right now (github.com/codewars) for JS and Ruby. Then we're developing a Docker/

Great questions guys - we use locked-down language sandboxes on our own servers right now (github.com/codewars) for JS and Ruby. Then we're developing a Docker/LXC based server sandbox that will allow us to safely run each code submission in any language in its own container... Another OSS option out there is: http://eval.so/ http://eval.so/