Can modding only be done via GUI?

I’m on a Mac, which shouldn’t be an issue but apparently is for test servers and other stuff, but what is the limitation if I can write the code for a mod anywhere? I’m used to glue scripting things together a la day to day normal linux admin stuff, including controlling graphical stuff through files written in vim inside screens in shells got to via ssh etc & etc, and could have been something if I’d kept learning MOO scripting, surely there’s ways to mod without some heavy dev kit or absolutely needing Windows?