SoloLearn offers tools for learning to code across multiple languages, available across web and multiple mobile platforms. The mobile-first apps focus on learning through community interaction including sharing of user-generated content and head-to-head challenges.
tags: c-plus-plus challenges educational educational-tool javaCodinGame is a challenge-based training platform for programmers where you can play with the hottest programming topics.
tags: challenge integrated-chat programmingThe online programming practice in java and python.
tags: java-compiler learn-a-programming-language programming pythonWanna pick up a new language without relearning code basics? DuoCoder is a language learning service by Jason Park
tags: programming programming-language reference