Mumble
Open Source
Mumble is an open source, low-latency, high quality voice chat software primarily intended for use while gaming.
Discord
Free
Discord is a freeware proprietary VoIP application designed for gaming communities.
Bit Chat
Open Source
Bit Chat is a secure, peer-to-peer, open source instant messenger with end-to-end encryption.
Viber
Freemium
Viber Free Messenger and Phone Calls.
Ring
Open Source
Ring (SFLphone) is an open-source SIP-compatible softphone and instant messenger for Linux, Microsoft Windows, OS X and Android.
Dialog Messenger
Free Personal
Dialog Messenger is a handy and feature-rich enterprise multi-device messenger available for server or cloud.
Compare TeamSpeak with alternatives
Compare Dialog Messenger and TeamSpeak and decide which is most suitable for you.