abicollab
Collaboration Software basierend auf AbiWord
http://abicollab.net/

AroundMe
Open Source Social Media Solution
Digital Identity, Social Networking

Blurt.it
Multimedia Microblogging Software
http://www.blurt.it/

CcHost
Multi Media Sharing, Collaboration
http://wiki.creativecommons.org/CcHost

Croquet
Collaboration Platform, 3D
http://www.opencroquet.org/

DirectSSO
Open Source Single Sign On Solution
http://www.single-signon.com/

dotProject
Projekt Management
http://www.dotproject.net/

eGroupWare
http://www.egroupware.org/

eLGG
Social Media Suite
http://www.elgg.org/

Gajim
Open Source IM Software
http://www.gajim.org/

GetBoo
Open Source Bookmarking System

Google Wave Protocol
Social Networking
http://www.waveprotocol.org/

Horde Project
Email, Messaging
http://www.horde.org/

Jabber
Instant Messaging
http://www.jabber.org/

Kolab
Groupware
http://www.kolab.org/

MySpace Qizmt
Social Media Software
http://qizmt.myspace.com/

Mugshot Project
Profile Aggregator, Activity Tracking

NewsCloud Open Source Media Platform
User generated News Plattform

OpenLaszlo
Plattform fuer Rich Internet Applications
http://www.openlaszlo.org/

openTimetool
Projekt und Zeit Management
http://www.opentimetool.de/

OS Tube
Social Media Video Portals
http://www.ostube.de/

PHPizabi
Social Networking, Community Software
http://www.phpizabi.net/

Pidgin
Open Source IM Software
http://www.pidgin.im/

Project JXTA
Open P2P Projekt
http://www.jxta.org/

Scuttle
Open Source Bookmarking System

Shareaza
P2P, File Sharing
http://www.shareaza.com/

sones GraphDB
Social Graph Solution
http://www.sones.de/

Tornado Web Server
Lifestreaming Software
http://www.tornadoweb.org/