Looking for Q&A Open Source / Free scripts

Guys can anyone suggest me some good free Q&A scripts ??

-It should have some good looking themes to start with
-facebook login integration !

Thank you very much in advance

 

These should do it. Others aren't worth mentioning for serious use.

1.OSQA
Website: http://www.osqa.net
Demo: http://meta.osqa.net

2.Qwench
Website: http://anantgarg.com/2009/12/09/php-stackoverflow-clone
Demo: http://anantgarg.com/qwench

3.Askbot
Website: https://github.com/ASKBOT/askbot-devel#readme
Demo: http://askbot.com/

4.Question2Answer (supports FB login)
Website: http://www.question2answer.org
Demo: http://www.question2answer.org/qa

 

Thank you very much for replying

FB login is must for me. So only Q2A has it, but there are no good looking themes

 

btw Qwench is real good, but no FB login

 

There's one more.

5.shapado
Website: http://gitorious.org/shapado
Demo: http://shapado.com/

It supports FB, Twitter, Google, OpenID login. Looks promising.

 

Looks good. How is suport / community / forums ? any idea ?

Thank you !