freepbx - FreePBX is a web-based open source GUI that controls and manages Asterisk (PBX).
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
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.
Genesys Cloud - As the foundation of great customer experience, the Genesys PureCloud contact center platform empowers your business to provide excellent service across the entire customer journey.
FusionPBX - FusionPBX is an open source FreeSWITCH GUI.
8x8 X Series - X Series connects teams across channels and around the globe, giving you access your most critical information securely, from any location.