A full-screen writing program or distraction-free editor is a text editor that occupies the full display with the purpose of isolating the writer from the operating system (OS) and other applications. Wikipedia

I wanted that with Vim. There are ways to do it. You can play with :winpos, lines and columns to achieve this (see here). There are scripts (1, 2). But all of these seemed complicated.

Here is a simple-but-not-perfect way to achieve this. This script just hide a couple of things and add a big margin on the left:

Go fullscreen with your terminal, and enjoy:

This is quite dumb, but it works very well for me. Let me know if you find ways to improve this.