Asterisk - An open source telephony switching and private branch exchange service for Linux.
Angle Audio - Live audio conversations as a service
Wazo.io - The UCaaS Platform Built for MSPs
Noor - Chat like you're in the office together
FreeSWITCH - FreeSWITCH is an open-source media application designed to support popular protools such as SIP and WebRTC and provides a platform to develop voice and video applications.
Orbital - Orbital is an Arcade, Puzzle and Single-player video game created by Bitforge Ltd.