Blink for Windows 5.2.0 (February 27, 2022; 2 years ago (2022-02-27)) [±] [2] Blink for Linux 5.2.0 (June 9, 2022; 2 years ago (2022-06-09)) [±] [3] 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).

[4][5] The software is written in Python for macOS's Cocoa, with a later port to Qt for supporting Microsoft Windows, Linux, AmigaOS.

[6][7] 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 RFB protocol (VNC), and SIMPLE presence using XCAP protocol.

[8] According to Jason Hibbets, an Advisor at Red Hat, Blink is a popular alternative to Skype[9] The Linux and macOS version of Blink implement OTR protocol end-to-end encryption and peer verification for chat media.

[6][10] All versions provide audio and video media encryption using ZRTP.