Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...

Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited

Vivox - Vivox is called to be one of the leading chatting platforms for online gamers.

Ripcord - A desktop chat client for Discord and Slack

Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.

Ziggs - Smoothly Share Content Between Devices!