A coworker of mine launched a Windows port (clone?) of emacs when he came in for the day, and never left it for the entire workday --- always envied him his facility with that, but never quite got comfortable with it (and even in a fit of pique gave away a printed copy of the LISP manual which I kind of regret now).

The ironic thing is I've been fascinated by similar graphical efforts such as the Glamorous Toolkit.