The Hessling Editor
Available from http://hessling-editor.sourceforge.net
A free implementation of the xedit/kedit editor concept(the IBM mainframe style editor, not the X Windows based editor).
Uses REXX as a macro/scripting langauge.
Has an interesting line/block oriented prefix command area that may be more intuitive than vi's command mode editing commands.
Is (roughly) as extensible as emacs but uses roughly 1/40 the disk space.
Allows muscle memory to be developed for keyboard command sequences allowing rapid editing for power users (similar to power of vi or emacs).