appear.in provides one-click video conferences right in your browser without requiring PIN codes or additional software.

CSipSimple is a Voice over Internet Protocol (VoIP) application for Google Android operating system using the Session Initiation Protocol (SIP).

Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication ov…

MicroSIP is a portable SIP softphone based on the PJSIP stack available for Microsoft Windows.

Ring (SFLphone) is an open-source SIP-compatible softphone and instant messenger for Linux, Microsoft Windows, OS X and Android.

Telephone allows you to make phone calls over the Internet or your company’s network.

Blink is the best real-time communications client using the SIP protocol.

Dasher Messenger provids a way to message friends.

Linphone is a free voice over IP (VoIP) service and SIP client.

QuteCom (WengoPhone) is a free-software SIP-compliant VoIP client.

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser cl…