
Description: Tango is a free and open source, cross-platform program for video calling and instant messaging using Voice over IP. It offers encryption, group conversations, file transfers, customizable user profiles, and other features.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Empathy is an open source instant messaging client that supports text, voice and video chat. It uses the Telepathy framework and integrates with the GNOME desktop environment. Empathy supports popular protocols like XMPP, IRC, Facebook Messenger, and more.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API