I recently used http://thereq.com/ http://thereq.com/ for a similar purpose. Features I liked: * I can set interview questions in various languages * Candi

I recently used http://thereq.com/ http://thereq.com/ for a similar purpose. Features I liked: * I can set interview questions in various languages * Candidate can write code right away, I can see everything he/she writes * Code can be executed to see the result right away * This even works for SQL, they have a sample schema the candidate can manipulate * They have a fairly large library of questions you can just add to your interviews * It's completely free as far as I can tell No affiliation with the site, but it was very useful for me.