The Community is a Free Software initiative building a unified communication and collaboration system that you can install on your own server. If you don't want to run your own server, consider using hosted Kolab like offered by

Community Tweets

#XKCD explains what #FreeSpeech really means: Besonders interessant für einige #Piraten.
Oberste Richter der USA zum #NSA Skandal: Wir sind nicht qualifiziert, müssen aber entscheiden.
Der @doktordab erklärt unterhaltsam, warum der Kampf “Print vs Online” blödsinnig ist:
I wonder why @republica gives a stage to @mikko from @FSecure and @DavidHasselhoff to sell their VPN and app.