I use Notepad ++ as my script editor when I’m working on large coding projects.
Because when Maya crashes it takes any unsaved script changes with it!
But being used to the MEL command highlighting in the Maya script editor I went hunting and turned up this:
Then I picked up a Maya-ish theme and modified the language to work with Maya Python syntax highlighting:
Put Waher-style in C:\Program Files (x86)\Notepad++\themes
put jbMayaPython in C:\Program Files (x86)\Notepad++\plugins\APIs
put userDifineLang in C:\Users\*USER*\AppData\Roaming\Notepad++
load the theme with notepad++’s theme loader then
select the language with the language dropdown.