List of free project-manager stuff for developer👇🏽
If you're looking for all programming tools around project-manager (not just free). Check this page List of project-manager Programming Tools
Focalboard is an open source alternative to tools like Asana, Trello, and Notion. Available as a stand-alone application or integrated into the Mattermost platform.
OpenProject is the leading open source project management software.
Free self host Community edition