http://h34nug3iwqjf2376fmmzdhgqivckzemcujmarlptfqeqtq7vya47yyad.onion/2008/08/31/devtodo-a-remindertask-program-aimed-at-developers/index.html
Each task in the list has a priority (very high, low, medium etc.) and a given task can be linked to another todo database, making the list hierarchical. The lists are stored as an XML file (.todo) in the current directory, so if you manage multiple projects, you can have different todo lists and DevTodo will update the information based on your current working directory.