Similar to Empathy_(ソフトウェア)

Presence information

Meebo

Messages (Apple)

WhatsApp

Voice over IP

Brekeke PBX

Gizmo5

Inter-Asterisk eXchange

H.248

Messenger (software)

Media Gateway Control Protocol

Tango (software)

TeamSpeak

Telecoms & Internet converged Services & Protocols for Advanced Networks

Tox (protocol)

Wide-coverage Internet Repeater Enhancement System

Asterisk (PBX)

Google Voice

Softphone