Today, I had a chat with ali on different online programming challenges as IOPC is going on write now and ali has taken part in it. I was remembering my glorious days when I won a jacket in bitwise.
I am just going to enlist a few programming challenges. Obviously, the list is not exhaustive.
1) ACM ICPC : I believe it is one of the most prestigious programming challenges. It is an IBM sponsored annual event.
2) Top Coder : This too is one of the most prestigious programming challenges. General belief is that the emphasis is more on programming rather than algorithms.
3) IOCCC : Well, here one can find the weirdest C programs. Most of the time it will seem that the winning entry programs won't even compile. However, they do but it is difficult ( rather next to impossible ) to find out what they would do by merely reading the code. My favorite program is here. And yeah, it DOES compile and run.
4) Bitwise : One of the most prestigious INDIAN programming challenges. I used the word "Indian" because it is held by Indian Institute of Technology, Kharagpur. The challenge however is open internationally. It is really a pity to see that since the inception of the event, only once an Indian team could grab the first prize. Ameya Karkare ( aka crack-kare ) and Navneet Lohiwal ( aka lollu ) from Indian Institute of technology Bombay (my alma-matter :-) ) played with handle "AK47", undoubtedly shooting down all competing teams.
5) OPC : Held annually by Chennai Mathematical Institute. One of the toughest programming challenge I have ever faced.
6) CodeCraft : Held annually by International Institute of Information Technology, Hyderabad as part of their technology festival Felicity.
7) IOPC : Hosted by IIT Kanpur as part of its technology festival techkriti.