dKosopedia

This looks interesting (shame about the name, which is hard to spell, pronounce and remember):

"Welcome to the dKosopedia, a collaborative project of the DailyKos community to build a political encyclopedia. The dKosopedia is written from a left/progressive/liberal/Democratic point of view while also attempting to fairly acknowledge the other side's take. It was started in April of 2004, and currently consists of 2831 articles."