FaceCode - Hire top tech talent with video interviews
codebunk - Realtime Collaborative Editor with Code Execution, REPLs and Chat
Daily Coding Problem - Get exceptionally good at coding interviews
Floobits - Floobits brings real-time collaborative editing to text editors, IDEs, and now Atom.
HackerEarth - HackerEarth is the network of top developers across the world. They connect to start-ups, tech companies, organizations and discover the best developer jobs. They participate in programming challenges and compete against other top developers.
coderpad - Collaborative code editor with in-browser, real-time execution. Conduct programming phone screens like a boss.