Blink (SIP client)
Blink is a Session Initiation Protocol (SIP) client distributed under the Blink license (GNU GPLv3 with an exception to permit the inclusion of commercial proprietary modules). The software is written in Python for macOS's Cocoa, with a later port to Qt for supporting Microsoft Windows, Linux, AmigaOS. == Features == Blink is based on the Session Initiation Protocol, and beyond voice over IP, its features also include video, instant messaging, file transfer and multi-party conferencing sessions based on MSRP protocol, remote desktop sharing using Remote Framebuffer (RFB) protocol (VNC), and SIMPLE presence using XCAP protocol.