Recommended Q&A Software

[mynewco]

So I just read an SEOMoz post about the great SEO benefits of Question and Answer sites (or sections of sites) - much like the Q&A section I'm in right now.

I did some googling and haven't really found a good software for implementing (installing, skinning, integrating, etc.) a Q&A section on my website. There are a few out there, but they are pretty basic, nothing like this site or Yahoo Answers.

Anyone know of good software (i'm on a PHP server) to implement Q&A on my site? Something that has the look and feel of this site or answers.yahoo.com, etc.?

Thanks for the help!

[AdoptionHelp]

There is a drupal distribution that does this: http://drupal.org/project/drupalanswers

[mynewco]

Thanks Ryan,

I've heard of drupal but never dealt with it  - do you have any idea what software runs SEOmoz's Q&A or, for example, this site: http://www.incorporationanswers.org/ ?

Thanks again