I think Sublime Text is pretty simple https://www.sublimetext.com/ https://www.sublimetext.com/. I still use version 3 because it's enough for me. You don't hav

I think Sublime Text is pretty simple https://www.sublimetext.com/ https://www.sublimetext.com/. I still use version 3 because it's enough for me. You don't have to install any packages, can hide the sidebar (I do); just have a simple window. Regarding autocomplete, I made my own. You can add files which contain only the words/keywords you want.