So, CodeHS wants to connect students with a real person to help them learn, offering debugging help and feedback on programming style, etc. as part of each exercise.

Karel is the obedient dog featured in the introductory, interactive programming exercises from CodeHS. It can perform basic functions--move in straight lines, turn, and fetch the ball. But Karel's ...

Called CodeH S, the company, co-founded by two recent Stanford University graduates, aims to provide online programming classes in high schools.