[zercool]

A site with free, open, community driven practice problems and solutions. Sort of like a wikipedia for questions. I could imagine this being a key ingredient in the future of OER. Would be cool to see something like this integrated with http://metacademy.org

[jwcrux]

Don't the stack exchange sites already serve for something like this?

[zercool]

Good point, actively contributing answers certainly helps practice a skill area. But I can't imagine thinking, "I need to practice tree traversal algorithms: to Stack Overflow!"

[zodiac]

I think his focus was on the "practice" in "practice problems and solutions. I can't really practice problems on SE.

[alagu]

You could try http://www.hackerrank.com/

[zercool]

Nice! Can I create questions myself? Also, is it only CS?