Contests

Programmer of the Month - A periodical problem solving contest for programmers from all over the world. Active forum.
http://dinsights.com/POTM/

The 1KB 6502 Programming Contest - Contest programming on the 6502 microprocessor. Valid programs must run on the 1 KB ram Microtan65.
http://oric.ifrance.com/oric/microtan/6502contest.html

Valladolid Programming Competition - An online contest with information about writing competitions, questions, and an online judge.
http://acm.uva.es/problemset/

International InfoMATRIX Computer Project Competition - Participants have to create a project for any of the categories (Programming, Design and Use of Computer, Desktop Publishing, Computer Art) First of all, each school must select one representant.
http://www.infomatrix.ro/

Al Zimmermann's Programming Contests - A series of programming contests that offer cash prizes. Any programming language may be used. These contests are conducted at irregular intervals, generally once or twice a year.
http://www.recmath.org/Contest

ICFP Programming Contest - Annual programming contest held in conjunction with International Conference on Functional Programming. Accepts submissions written using any programming language.
http://alliance.seas.upenn.edu/~plclub/cgi-bin/contest/

BUTE Budapest International 24-hour Programming Contest - Annual 24-hour contest hosted by Budapest University of Technology and Economics. The contest is open to a limited number of international teams of 3 people via an internet qualifying round.
http://www.challenge24.org/

MiniGame Compo - Contest to write a fully playable game in under 1K or 4K. Open to games for classic 8-bit computers.
http://minigamecomp.org.uk/

RAD Race - 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.
http://www.radrace.org/

OpenChallenge - 3-monthly challenge. Every three months the innovations are published under GNU GPL/FDL licenses.
http://www.openchallenge.org/

Project Euler - A series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve.
http://projecteuler.net/

TopCoder - 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.
http://www.topcoder.com/

Bitwise - An annual online programming contest organized by the Computer Science and Engineering Department Society of IIT Kharagpur. Information on the contest, sponsors and resources.
http://www.bitwise.iitkgp.ernet.in/

MacHack - Annual Macintosh programming contest and convention.
http://www.machack.com/

The Robot World Cup Initiative - Soccer playing computers.
http://www.robocup.org/

Swiss Olympiad in Informatics - The SOI is a national programming contest for people up to 20 years in age.
http://www.soinf.ch/

Teamwork in Programming Contests - Tips and observations from a team of programmers who have regularly won in the ACM programming contests. Published in ACM Crossroads, the student magazine of the ACM.
http://www.acm.org/crossroads/xrds3-2/progcon.html

The International Obfuscated C Code Contest - A contest to write the most obscure/obfuscated C program.
http://www.ioccc.org/

International Contest for ICCS - Programming contest disseminated by the Nalini Foundation in five categories: computation, simulation, graphic patterns, words, mind benders.
http://iccs.8m.com/

OpenECG Programming Contest - A programming contest for Electrocardiography record handling applications and tools, using the SCP-ECG Standard.
http://www.openecg.net/

Loebner Prize - A unique annual contest in which a winner is selected from participants who comes to the closest to demonstrating that machines can think like humans, as per the Turing Test.
http://www.loebner.net/Prizef/loebner-prize.html

2002 MiniGame Compo - Aim is to write a game in 1024 bytes of code, for an 8-bit home computer such as the Atari 2600, NES, CPC+, or TI99/4A. Includes competition news and details of entries.
http://www.cling.gu.se/~cl3polof/minigame/

RoShamBo Programming Competition - A Rock-Paper-Scissors programming competition.
http://www.cs.ualberta.ca/~darse/rsbpc.html

C++ Robots - C++ based robots programming challenge.
http://www.gamerz.net/c++robots/

Loco Mummy (Low Cost Multimodal Interface Software Contest) - Contest calls for new communication helper software between humans and PCs or PocketPCs. Free. Open to all. Various prizes.
http://www.locomummy.net/

JRobots - Java-based Robots Programming challenge.
http://jrobots.sourceforge.net/

Sphere Online Judge - Problemset archive, online judge and contest hosting service accepting solutions in C, C++, Pascal, Java and other languages.
http://www.spoj.pl

DSAP - Data Structures + Algorithms = Programs. Algorithm materials and programming problems from informatics contests.
http://vnco.lubox.net/

Internet Programming Contest - Duke University sponsors a programming contest that takes place in real-time over the internet.
http://www.cs.duke.edu/~ola/ipc.html

iDevGames : uDevGame Contest - An annual event that promotes game development on the Macintosh computer.
http://www.idevgames.com/

Internet Problem Solving Contest - Online programming contest for teams, open to anyone.
http://ipsc.ksp.sk/

Programming Contest Problems Archive - If you are preparing for a programming contest, this page might be useful. Includes past problems of national, regional and international contests.
http://www.inf.bme.hu/contests/tasks/