Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Wekan, formerly LibreBoard, is an open-source and collaborative Trello -like kanban board application.
Taiga is the easy and intuitive yet powerful agile project management tool for multi-functional teams. Taiga has a best in class Sprint task board, and you can seamlessly migrate to Kanban if needed.
Kanboard is a free and open source Kanban project management software.
Open source Trello-like kanban board. Based on Restya platform.Discontinued
The last update is from March 2022 and the official website is unavailable, so this might project might be abandoned.