GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.
Clever - syncing between education applications for K-12 schools
Gerrit Code Review - OpenSource Git Code Review Tool
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
Phabricator - Phacility - Phabricator
Claroline - Claroline is a collaborative eLearning and eWorking platform.