Bitwise
- http://www.bitwise.iitkgp.ernet.in/
- An annual online programming contest organized by the Computer Science and Engineering Department Society of IIT Kharagpur. Information on the contest, sponsors and resources.
International Contest for ICCS
- http://iccs.8m.com/
- Programming contest disseminated by the Nalini Foundation in five categories: computation, simulation, graphic patterns, words, mind benders.
Project Euler
- http://projecteuler.net/
- A series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve.
RAD Race
- http://www.radrace.org/
- The Rapid Application Development Race is a programming competition open to any kind of development tool and/or language. The RAD Race focuses on real life business and administrative programming and not on algorithm development.
RoboCom
- http://www.cyty.com/robocom/
- An online game for programmers. Participants determine how robots will move, communicate with others or even build more robots.
Sphere Online Judge
- http://www.spoj.pl
- Problemset archive, online judge and contest hosting service accepting solutions in C, C++, Pascal, Java and other languages.
TopCoder
- http://www.topcoder.com/
- Online computer programming competitions in the Java, C++, and C# languages. Competitions take place twice a week, and members can win from $25-$300. Major tournaments have a prize purse of $250,000.