Linphone - Video SIP phone for Desktop and Mobile

•    C

Linphone is an internet phone or Voice Over IP phone (VoIP), it helps to communicate freely with people over the internet, with voice, video, and text instant messaging. Linphone is available for Linux, Windows, MacOSX, and for mobile phones: Android, iPhone, Blackberry. It is using SIP protocol and it is compatible with any voip operator using SIP for its network.

Qutecom - PC to PC Video and Voice calls

•    C++

QuteCom is a SIP compliant VOIP client. It allows users to speak to other users of SIP compliant VoIP software. It helps to make calls to landlines, cellphones and allows to send SMS and make video calls.

Ekiga - Software Phone and Video Cnferencing Application

•    C++

Ekiga (formely known as GnomeMeeting) is an open source SoftPhone, Video Conferencing and Instant Messenger application over the Internet. It provides Audio and Video free calls through the internet. It supports standard telephony features like Call Hold, Call Transfer, Call Forwarding, Call Histroy and Call Monitoring.

Blink - easy to use SIP client

•    Python

Blink is a GUI for Mac, Windows and Linux built on top of SIP SIMPLE client SDK. It uses SIP (Session Initiated Protocol) for VOIP and Instant Messaging. It supports Multi-party conferencing, Missed Calls, Dialing out SIP addresses and telephone numbers. Currently File Transfer and Desktop sharing is supported only in Mac.

Empathy - Instant Messaging for GNOME

•    C

Empathy is a messaging program which supports text, voice, and video chat and file transfers. It supports private and group chat and logs the complete conversation. It currently lacks privacy and encryption support.

SFLphone - Softphone for Linux

•    C++

SFLphone is a softphone for Linux. It is SIP compatible and supports Multi-way conferencing, Peer to peer calls, Video calls, Instant Messaging, Multi-line, Call transfer, Call hold, Call recording and lot more. It encrypts voice using SRTP protocol.

jitsi-android - Jitsi for Android is an Android port of the Jitsi project: The most feature-rich communicator with support for encrypted audio/video, chat and presence over SIP and XMPP

•    Java

The development of Jitsi for Android has been stopped in early 2015. Issues and Pull Requests will not be addressed. Jitsi for Android is an Android port of the Jitsi project: The most feature-rich communicator with support for encrypted audio/video, chat and presence over SIP and XMPP.

Matrix - Decentralized group communication

•    Python

Matrix is an open standard for decentralised communication, providing simple HTTP APIs and open source reference implementations for securely distributing and persisting JSON over an open federation of servers. It can be used for Decentralised Group Chat, WebRTC signalling, Internet of Things, VOIP etc.

linphone-iphone - Linphone is a free VoIP and video softphone based on the SIP protocol

•    Objective-C

Linphone is a free VoIP and video softphone based on the SIP protocol. Interested in helping translate Linphone? Contribute on Transifex.

Mumble - High Quality Voice Chat Software

•    C++

Mumble is a cross-platform voice over IP application. It is a client - server application where multiple users could use the same server and all their communication is encrypted. It could be used while gaming. It does audio video recording.

Jitsi Videobridge - WebRTC compatible video router or SFU that lets build highly scalable video conferencing infrastructure

•    Java

Jitsi Videobridge is an XMPP server component that allows for multiuser video communication. Unlike the expensive dedicated hardware videobridges, Jitsi Videobridge does not mix the video channels into a composite video stream, but only relays the received video channels to all call participants. Therefore, while it does need to run on a server with good network bandwidth, CPU horsepower is not that critical for performance.

Telephone - SIP softphone for Mac

•    Swift

Telephone is a VoIP program which allows you to make phone calls over the internet. It can be used to call regular phones via any appropriate SIP provider. If your office or home phone works via SIP, you can use that phone number on your Mac anywhere you have decent internet connection. Opus codec is optional.

linphone-android - Linphone

•    C

Linphone is a free VoIP and video softphone based on the SIP protocol. Download the Android sdk (API 28.0.0 at max) with platform-tools and tools updated to latest revision, then add both 'tools' and 'platform-tools' folders in your path and the android-sdk folder to ANDROID_HOME environment variable.

skype2rtc

•    Java

VoIP (Skype) to analog phone line (PSTN) gateway. Allows you to share your phone line over Internet using Skype.

Kamailio - The Open Source SIP Server

•    C

Kamailio (successor of former OpenSER and SER) is an open source implementation of a SIP Signaling Server. SIP is an open standard protocol specified by the IETF. The core specification document is RFC3261.

react-native-incall-manager - Handling media-routes/sensors/events during a audio/video chat on React Native

•    Java

Basically, it is a telecommunication module which handles most of requirements when making/receiving/talking with a call. note: you might need android.permission.BLUETOOTH permisions for Bluetooth to work.

RocketChat - The ultimate open source web chat platform

•    Coffeescript

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework. It is a great solution for communities and companies wanting to privately host their own chat service or for developers looking forward to build and evolve their own chat platforms. Its features include File sharing, Video conferencing, Screen sharing, Live chat, Link preview and lot more.

holla - An abstraction over P2P video/voice/data connections using WebRTC

•    Javascript

Pipes a WebRTC video stream to a video element. el can be a string (id), jquery element, or dom node.

NTP-VoIP Chat

NTP-VoIP chat is a sample VoIP based chat client (and server) developed for academic purposes at the Faculty of Electrical Engineering in Sarajevo. It uses standard protocol stacks (SIP, RTP) to enable voice communication between clients

Jitsi Meet - Secure, Simple and Scalable Video Conferences

•    Javascript

Jitsi Meet is an open-source (Apache) WebRTC JavaScript application that uses Jitsi Videobridge to provide high quality, secure and scalable video conferences. Jitsi Meet allows very efficient collaboration. Users can stream their desktop or only some windows. It also supports shared document editing with Etherpad.