FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a versatile software implementation that runs on any commodity hardware. From a Raspberry PI to a multi-core server, FreeSWITCH can unlock the telecommunications potential of any device.

The official Asterisk Project repository.

Kamailio - The Open Source SIP Server for large VoIP and real-time communication platforms -

HOMER - 100% Open-Source SIP, VoIP, RTC Packet Capture & Monitoring

⚡ The future of programmable SIP servers.

OpenSIPS is a GPL implementation of a multi-functionality SIP Server that targets to deliver a high-level technical solution (performance, security and quality) to be used in professional SIP server platforms.

Official FusionPBX - A full-featured domain based multi-tenant PBX and voice switch for FreeSwitch.

Linphone.org mirror for flexisip (git://git.linphone.org/flexisip.git)

📞 Open Source Telephony API Platform