Who is Yii?

Who are the developers behind Yii?

When im looking in the SVN i only see qiang xue & weizhuo… are there any plans to let more people into the development team?

Yes, right now only Wei and me. Please see http://www.yiiframework.com/forum/index.php?/topic/3920-recruiting-new-team-members/

Also there are multiple translation teams: http://code.google.com/p/yiidoc/source/browse/trunk/members.txt