You use the tab key to make an item a "child" of the previous item; in other words, to create hierarchical lists.

In other words, you can compose, format, and manage your lists by simply typing text--you never have to take your fingers off the keyboard. (Bonuses: TaskPaper auto-completes tags as you type, and all but a few of TaskPaper's menu commands are also accessible via keyboard shortcuts.) If, like me, you're a keyboard-oriented person, you'll love the convenience--and freedom--of this approach.

TaskPaper also offers several useful ways to view your lists. By default, all the projects in a document are shown at once. But if you click on the arrow icon in front of a project name, or choose that project's name from the Project Navigation pop-up, the view shifts to focus on just that project; click on the arrow again to switch back to the default view. Alternatively, if you want to focus on just a single project, Command+click on the project's name to open it in a new, Safari-like tab within the same window; you can open each project in its own tab, if you like. (Unfortunately, you can't rearrange tabs as you can tabs in Safari.) Finally, you can reveal TaskPaper's Projects List, which changes the program's interface considerably. Instead of showing all projects in a single view, TaskPaper displays only a single project at a time, along with a list of projects on the left-hand side of the window; click on a project name to view it. You can also combine these features: You can view the full list in one tab, while using the Projects List in another.

(Each time you open a new document, it includes instructions for using the program; to start working, just Select All and delete. When I first started using TaskPaper, having this text handy each time I started a list helped me quickly learn the program's formatting and viewing options. Once you're familiar with TaskPaper, you can disable this feature.)

While testing TaskPaper, I found it to be right in my personal "sweet spot" between too basic and too complex. But there's one other thing about TaskPaper that's unique: TaskPaper works all this magic using plain text. That's right: TaskPaper documents are text files, viewable in any text editor or word processor. When you type a colon to designate a project, you really are just adding a colon to the end of a line of text; when you type @done to tag a task as done, you really are just adding the text @done to a line of text. TaskPaper interprets those simple characters to produce the formatted appearance you see on the screen.