Guru99 is described as 'We at Guru99 strive to make quality education affordable to the masses. Over the years the cost of education has increased many folds to make it beyond the reach of many'. There are more than 10 alternatives to Guru99, not only websites but also apps for a variety of platforms, including Android, iPhone, Mac and Windows. The best alternative is Codecademy, which is free. Other great sites and apps similar to Guru99 are W3Schools (Free), tutorialspoint (Free), Grasshopper (Free) and Codeasy (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.
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.