Notepad++ uses Scintilla, the core component of GTK+ editor SciTE, so that basically any non-Windows platform that runs X11 is covered.
Notepad++ is somewhat nicer though.
Sublime Text on the other hand feels simultaneously like a fresh break from the Emacs tradition and like a true gem among the proliferation of half-baked notepad replacements like notepad2 (Scintilla-based, too), gedit or Kate.
It adopts best features from Vim and TextMate in a surprisingly clean way.
