I am looking for a tool that will let me work on a dependency graph. (I want this for my personal tasks, like a to do list.) Like, let's say I have task 1, 2 and 3. Then maybe task 1 is needed for task 2, and task 1 is partially needed for task 3, and task 2 is needed for task 3, etc. I should be able to edit easily, change relations between tasks easily, and have a nice graphical view of the graph.
Do you know of anything like that?