Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Taskwarrior - Taskwarrior is an ambitious project bringing sophisticated capabilities to a simple and elegant...
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Scheduled tasks - GNOME GUI for configuring a users' cron (automatic jobs). Some of its features are:
DevTodo - To-do list for Chrome DevTools.
Taskbook - Like Trello but for the Terminal