
Description: Zulip is an open-source team chat software that focuses on threaded conversations to improve productivity and organization. It has features like public/private streams, emoji reactions, integrations, and customizable notifications.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Nimbuzz is a free messaging and calling app for smartphones and desktop. It allows users to connect with friends, groups and communities worldwide across various platforms including MSN, Yahoo, AIM, ICQ, Hyves, GTalk and Facebook.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API