Drupal

From dKosopedia

Drupal is an open source web community system which is being used to power a number of civic and political web-spaces. It is highly extensible and has modules for blogs, calendars, forums, image galleries and more. Notable political adaptations include DeanSpace and CivicSpace.

Outlandish Josh created a Drupal filter module to allow other websites to more easily reference the dKosopedia. You can read about it and download the module from this dKos Diary Entry