Although there are numerous cocoa/carbon outliners and organizers available, as far as I can tell TAO is the only one to implement cloning -- and this alone makes TAO stand out from the throng. Cloning, for the uninitiated, allows an an item to be on various sublists, with a change to one applied to all.

Cloning must be a bear to code, since a half-dozen other programmers say it's on their feature request list but nothing ever comes of it.

Incidentally, Takashi T. Hamada's licensing scheme allowing a user two installs seems fair to both us and him, and will only offend those who expect a de facto site license for the basic payment. The demo version seems fully enabled, albeit with frequent pop-up reminders.