For years I used a similar program called KeyNote. It had an absurd amount of text tricks up its sleeve and everything was accessible via keyboard shortcuts. Most people would cringe at its late 90s GUI (it's Borland Delphi!), but after hiding a couple toolbars and palettes, it became quite the handsome app.

http://tranglos.com/free/keynote.html

Unfortunately it's Windows-only. Now I only work on Linux and Mac and the only software that approaches it's level of usability is Notational Velocity.