Atom (https://atom.io/)-highly suggested for Mac users. Allows browsing between different folders and projects. Highlights commands. Many personal configuration choices for users.

Sublime Text (https://www.sublimetext.com/) - similar interface with Atom.

Avoid BBeditor (old TextWrangler). Not convenient, does not seperate commands.

Emacs

Nano - not recommended

Vim - takes some getting used to, but vim/vi should be installed everywhere. Tutorial: https://vim.fandom.com/wiki/Tutorial, also see Vim, Cheatsheet: https://vim.rtorr.com/ and https://devhints.io/vim