Taskbook - Like Trello but for the Terminal
Todour - Todour is an application for handling todo.
dstask - Command line todo list with git sync
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Calcurse - Calcurse is a calendar and scheduling application for the command line.
Everdo - The last to-do and GTD app you'll ever need