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