Open Source PHP script/lib/cms for creating sites a-la StackOverflow?

Question

I want to create site a-la StackOverflow but for different needs (not for Questions at all) (for some crazzzy geo mapping project=) so I need CMS... I vant it to be looking like StackOverflow...

So is there any Open Source PHP script/lib/cms for creating sites a-la StackOverflow?

Answer 1

Somebody built a stack overflow clone on top of the drupal plattform: ArrayShift (demo site). It might perfectly fit your needs, having the very strong drupal cms below the stack overflow functionality.

Answer 2

I highly recommend Silverstripe for the purpose, http://www.silverstripe.org/, since I started using it I've recommended clients to do the transfer from Drupal and Joomla whenever possible.

Answer 3

PHPBB?

(This is a joke. Please don't down-vote me.)