Coderbyte is described as 'place built for anyone to practice and perfect their programming skills. Challenges are added almost every day so you can work on applying your algorithmic thought process on any problem you want at anytime' and is a Code Learning service in the development category. There are more than 50 alternatives to Coderbyte, not only websites but also apps for a variety of platforms, including Android, iPhone, Android Tablet and iPad. The best alternative is freeCodeCamp, which is both free and Open Source. Other great sites and apps similar to Coderbyte are Coursera, Codecademy, SoloLearn and W3Schools.
Code.org is a non-profit whose goal is to expose all students to computer programming. We believe that computer programming is a liberal art; it's something EVERY student in the world should be exposed to at some point in their childhood education.