if you’re asking about for a team, i’d recommend redmine or open project. if for an individual i’d recommend pen and paper, org mode, or logseq (in that order). as far as pen and paper systems go, i like bullet journaling because it combines mindfulness self care with the the trappings of a productivity tool. japanese planners like the hobonichi on kokuyo jibun are also excellent at this. the other direction to go is to do a kanban wall just like what trello is simulating