Similar to Inter-Asterisk_eXchange

FaceTime

Gizmo5

Jami (software)

Jitsi

Facebook Messenger

Mumble (software)

OSIP

Skype

Tango (software)

TeamSpeak

Telecoms & Internet converged Services & Protocols for Advanced Networks

Tox (protocol)

Wide-coverage Internet Repeater Enhancement System

Asterisk (PBX)

Ekiga

Empathy (software)

KakaoTalk

Google Hangouts

Google Voice

Zoom (software)

Softphone

Discord