The calendar in the screenshot is misleading; the power of this tool comes from: (1) being always available (who doesn't have a terminal open?) and (2) having a powerful command language.

It's the only todo tool that I actually use. It removes the friction of having to have a web-based one open, find the window/tab, click on the appropriate textbox, etc.

The devs listen to comments, and think carefully new features. I was added to the list of contributors for 2.0 just because of an idea I suggested. Very active project. Cannot recommend enough. Our startup uses it instead of a whiteboard.