SocialEngine - Socialengine PHP: Elevating Your Online Community Experience.
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
Diaspora - The online social world where you are in control.
Clever - syncing between education applications for K-12 schools
JomSocial - Open Source Social Networking Software. Award winning open source community software by JomSocial. This social networking software is widely used by many Joomla users.
Claroline - Claroline is a collaborative eLearning and eWorking platform.