Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...
TeamLink - TeamLink is one of the leading and sumptuous solutions that is making web and video meetings extremely easy and efficient.
GSC - With GSC, you can pick from any of 14 worldwide datacenters to host your own free voice server.
GoRemote - A free & simple yet powerful European based solution to go remote. Video & audio conferences, screen sharing & chat with end to end encryption. Keep your team close and productive
Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
Google Duo - Google's answer to Facetime, high-quality video calling on iOS and Android.