Codeforces are doing well in developing a no. of quality coders. As i joined codeforces(cf) very early but start participating in the contests now and what i found is that the way of hosting the contest and offcourse the hacking and System Testing process i liked much.Yeah..the questions are always tricky and short if u go in the right direction that's the most important thing attracted me. So thank you cf for providing such a platform to us.