### Index
* [Competitive Programming](#competitive-programming)
* [Problem Sets] (#problem-sets)


### Competitive Programming
* [4Clojure](http://www.4clojure.com/)
* [Codeabbey](http://www.codeabbey.com/)
* [Codechef](http://www.codechef.com/contests)
* [Codeeval](https://www.codeeval.com/)
* [Codeforces](http://codeforces.com/)
* [Coderbyte](http://coderbyte.com/)
* [Codingame](http://www.codingame.com/start)
* [Facebook Hackercup](https://www.facebook.com/hackercup)
* [Hackerrank](https://www.hackerrank.com/)
* [Hello World Open](https://helloworldopen.com/)
* [Internet Problem Solving Contest](http://ipsc.ksp.sk/)
* [Just another Golf Coding](http://jagc.org/)
* [Topcoder](https://www.topcoder.com/)


### Problem Sets
* [Anarchy Golf](http://golf.shinh.org/)
* [Caribbean Online Judge](http://coj.uci.cu/24h/problems.xhtm)
* [CheckIO](http://www.checkio.org/)
* [Coding Bat](http://codingbat.com/java)
* [Google Code Jam - Practise](https://code.google.com/codejam/contests.html)
* [Hacker.org](http://www.hacker.org/)
* [Mathproblem of the Month - Bilkent University](http://www.fen.bilkent.edu.tr/~cvmath/prob-month.html)
* [PKU Online Judge](http://poj.org/)
* [Ponder This!](http://domino.research.ibm.com/Comm/wwwr_ponder.nsf/pages/index.html)
* [Project Euler](https://projecteuler.net/)
* [Sphere Online Judge](http://www.spoj.com/)
* [Timus Online Judge](http://acm.timus.ru/)
* [UVa Online Judge](http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8)