Novocall is an international callback software to help you capture and distribute qualified sales call leads for inside sales and sales teams.
Asterisk - An open source telephony switching and private branch exchange service for Linux.
Callpage - Turn website visitors into sales calls. Use CallPage and provide immediate free phone callback to your leads in 28 seconds.
FreeSWITCH - FreeSWITCH is an open-source media application designed to support popular protools such as SIP and WebRTC and provides a platform to develop voice and video applications.
LiveCall - LiveCall is a callback software that enables users to talk by voice with people who are currently visiting a website in 25 seconds.
FusionPBX - FusionPBX is an open source FreeSWITCH GUI.
Inbound Rocket - Converts visitors into leads, subscribers & customers