It's not wordpress and it's not DLE or Joomla. It probably started out as a very simple lightweight CMS like wolfcms or something like that but has being customized a massive amount with javascript like MarkItUp and ZeroClipBoard and Flash like Dock Menu FX so much so you may as well say it's 100% custom coded now.

Again it it NOT wordpress, DLE or Joomla. It's a really nice and well coded site. I'll be visiting it more often.


edit. It started as http://codeigniter.com/ but it heavily customized with the above mentioned scripts and flash.