Here’s a site that has maths problems to solve, with a ranklist and a judge. You can also add problems.
Here’s the link, and do tell me here if you like it. MathWizard
First few problems are more computational, but towards the end of the problem list you’ll find interesting problems. And you can also discuss about various matters there on the Disqus.
I’ll edit this post notifying of other changes.
UPD: A new top 10 list has been made.
UPD: A new badges feature is added. Badge qualifications will be detailed shortly.
UPD: A new country name feature is added. Please add your country name on the site on the problems page.
UPD: A much needed feature, ie discussions for individual problems, has been now added. You
can access it by opening the desired problem and by clicking on the link there.
UPD: There was a problem here…which is now hopefully fixed. Any abnormalities found…please report on the main disqus (The tab ‘Disqus’ at the top)!
UPD: MathML(using MathJax) support has been added.
UPD: A problem search facility has been added.
UPD: MathWizard Admin (Problem Setting) Board established. You can also participate, if you wish to contribute good problems!
UPD: Editorial feature added. After solving a problem you’ll get the editorial by clicking
on the tick mark that appears beside it (provided it has been written).
For problem-setters: Please write the editorials for your problems as soon as
possible. You can do this, by opening the problem. Then click on the Write/Edit The
Editorial option to write/edit the editorial for the problem.
UPD: Relative Difficulty Score for problems has been added.