All kinds of events and workshops are held here (ranging from screen printing and Photoshop classes to Yoga and political discussions), and various initiatives use it for meetings (Funkfeuer, IG Filmen, etc).
There's a political, leftist/activist slant to the place.
It's open to the public Monday to Friday from 2 to 8 pm. If this review made you curious, stop by and let the friendly people there show you around and explain the idea.