Many languages are supported, and the ability to use Vim keybindings. It's not easy to replicate a coding environment that everyone will be happy with, but making the attempt is appreciated.
I've worked with another similar tool before, but CoderPad is just a lot better. It supports several languages, SQL including the possibility to store tables to work with.
We extensively use the interview pair programming functionality, as well as take home exercises, in which people submit their code for us to review.