Rocket.Chat - Free, Open Source, Enterprise Team Chat
ReqView - Free Requirements Management Software Tool
Xmind - Full-featured mind mapping and brainstorming tool.
yEd - Graph Editor
Jami
Home - Pencil Project
Ferdi
Focalboard: Open source alternative to Trello, Asana, and Notion
DistroTest.net - The first online operating system tester
OnWorks Free hosting provider for Linux online