Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...
Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
RaidCall - Free & Light. Setting up is fast and easy; with no need to rent or set up servers. Low CPU usage and minimum memory footprint allows for smooth, uninterrupted communication. im. Group Communication.
Twitch - Twitch is one of the most prominent streaming services around, serving as a platform primarily for video game and pop culture streamers.
GSC - With GSC, you can pick from any of 14 worldwide datacenters to host your own free voice server.
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.