Vim

Vim is a configurable, open source, and cross platform text editor that is an improvement of the vi editor in most Linux distros.

It has nifty things like syntax highlighting, colorization, and a scripting language to make your own plugins, etc.

Setup

As aforementioned, it is cross platform (and open source), so it can run on anything (even Potato). Personally, I prefer to use it on Linux only because it is usually in the default repository and has both syntax highlighting and colorization, which are a great improvement upon vi in CLI.

Linux

If your distro does not have vim in its default repo, then I fear you will have to compile from source code.

Windows

If you should want to use Vim on Windows, and not use gVim at PA.com, then both binaries and executables are available for you.

Other

Believe it or not, Vim is available on even more architectures: Amiga, OS2, Macintosh, Android, iOS, WindowsCE, Cygwin, and others.

Plugins/Scripts

Vim has a library of thousands of powerful scripts that are easy to make if it is missing something you want. Personally, I do not use any since I mainly use Vim as a quick, light editor.