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.

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.