Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
Clever - syncing between education applications for K-12 schools
GSC - With GSC, you can pick from any of 14 worldwide datacenters to host your own free voice server.
Claroline - Claroline is a collaborative eLearning and eWorking platform.