
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: Telephone is an open source SIP softphone and VoIP client for making audio and video calls over the internet. It supports standard telephony features like call waiting, call forwarding and voicemail.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API