In an earlier article, guest author Martin Michlmayr reviewed the todo.txt and
Taskwarrior task managers. This article continues the process of examining task
managers by looking at tools for Org mode, which is a system originally created for Emacs, as
well as at tools that make use of the iCalendar standard. It is time to find
out whether he can find a system that meets his needs.

Source: LWN.net – [$] Managing tasks with Org mode and iCalendar