Focuster - Ditch your todo list for an intelligent scheduler
Taskbook - Like Trello but for the Terminal
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
dstask - Command line todo list with git sync
Calcurse - Calcurse is a calendar and scheduling application for the command line.
Nirvana - Nirvana is a web-based GTD task manager.