Hi,
I was not able to find a syntax coloring definition for gcode in gtksourceview (gedit) so I made one.
It helps me when I´m reading through my gcode so I thought It might help others if I shared it..
it´s far from perfect, but it´s a start
http://dl.dropbox.com/u/22370817/ngc.lang
drop it in either .gnome2/gtksourceview-2.0/language-specs/ or /usr/share/gtksourceview-2.0/language-specs/
Henrik