Wow, vi/vim vs emacs, what a temptation...
From a vi-user's perspective...
- Always There
vi is on about every unix system ever released, in the default install, and available for Win
- May save you from RSI
vi uses home-row keys for just about everything, modifiers like control and meta are used only for rarely invoked functions and even shift-key use is moderate. This was probably all just a lucky accident, but don't laugh at RSI. It can happen to anyone, it's seriously painful, it's potentially career-ending, and it's hard to treat.
- Starts up instantly.
In the past, this was a huge advantage over emacs. Emacs users had to start up just once, and navigate everywhere within emacs. Today it starts faster, but in vi, it's perfectly reasonable to quit out of it entirely on every compile or test cycle.
- Has an awesome line-mode
The line mode in vi is backwards compatible to the original Unix ed(1) program, an editor that had only a line mode. That is, vi's regular-expression-substitution-engine-/-line-editor was once an editor all by itself.
- Easily scriptable
Got something you want to do to every .whatever
file in your project? It's easy to write a declarative script that will edit a sequence of files. No need for imperative or procedural programming.
- Easily extensible
Vim, at least, can be extended in Python.