The best free alternative to Coderbyte is freeCodeCamp, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Coderbyte and loads of them is free so hopefully you can find a suitable replacement. Other interesting free alternatives to Coderbyte are Codecademy (Freemium), Coursera (Freemium), SoloLearn (Freemium) and W3Schools (Free).
Interactive platform for learning C# where you learn coding by reading an adventure story about fighting machines in the future. While reading you gonna meet challenges that require real coding to solve.
Sphere Online Judge created for the coders' community to train, to learn and to make progress. With thousands of programming problems and an international group of users Spoj is one of the best programmers' communities and online judges in the world.
A Computer Science portal for geeks. It contains well written, well thought and well-explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions.