What are some alternatives?
When comparing exercism and Robocode, you can also consider the following products
Hackr.io - There are tons of online programming courses and tutorials, but it's never easy to find the best one. Try Hackr.io to find the best online courses submitted & voted by the programming community.
CodeSignal - CodeSignal is the leading assessment platform for technical hiring.
Geocities Site Builder - Share your abomination with the world
Human Resource Machine - Tomorrow Corporation is an independent game developer behind indie games Little Inferno and Human Resource Machine
Codecademy - Learn the technical skills you need for the job you want. As leaders in online education and learning to code, we’ve taught over 45 million people using a tested curriculum and an interactive learning environment.
Codewars - Achieve code mastery through challenge.