QuteCom

QuteCom (previously called WengoPhone) is a free-software SIP-compliant VoIP client developed by the QuteCom (previously OpenWengo) community under the GNU General Public License (GPL). It allows user...
Language(s): C, C++, Qt
Operating system(s): Cross-platform
License: GNU General Public License

Ring

Ring is a free and universal communication platform which preserves the users' privacy and freedoms. Ring is free software for universal communication which respects the freedoms and privacy of its us...
Language(s): C, C++
Operating system(s): Linux, FreeBSD, Microsoft Windows, OS X, Android
License: GNU General Public License v3

SipXecs

Revolutionary platform that delivers a complete set of communication and collaboration applications on an enterprise-ready platform optimized for hybrid cloud hosting and delivery as a service. It d...
Language(s): N/A
Operating system(s): CentOS, RHEL
License: Affero General Public License

Tox

Whether it's corporations or governments, digital surveillance today is widespread. Tox is easy-to-use software that connects you with friends and family without anyone else listening in. While other ...
Language(s): C
Operating system(s): Windows, Linux, OS X, Android, iOS, FreeBSD, OpenIndiana, Sailfish OS
License: GNU General Public License v3

Twinkle

Twinkle is a free and open-source app for voice communications over Voice over IP (VoIP) protocol. It is designed for Linux operating systems and uses the Qt toolkit for its graphical user interface. ...
Language(s): C++
Operating system(s): Linux
License: GNU General Public License