Hello, I'm Sean and I'm currently doing my thesis for my Computer Science degree and it's about the gamification of online judges. If you've got a few minutes of spare time kindly answer our survey. Thank you!
https://docs.google.com/forms/d/1iwJz7skZlDwrdq8pCwjUaeikd3xb9bd3DBYS_v_jJAQ/viewform
Oh the irony... No codeforces...
codeforces is perfect, he knows that
Seriously,how the hell you didn't mention Codeforces :o :o :o
He just started using Codeforces(His first submission was on 21st Sep. 2015). Maybe he'll add it later.
That was a long survey!