Wikipedia
CodeChef
CodeChef is a non-profit educational initiative of Directi. It is a global competitive programming platform which supports over 50 programming languages and has a large community of programmers that helps students and professionals test and improve their coding skills. Its objective is to provide a platform for practice, competition and improvement for both students and professional software developers. Apart from this, it aims to reach out to students while they are young and inculcate a culture of programming in India.