Emacs
From AdminWiki
Emacs is arguably the most powerful text editor in existence. It's power is derived from it's extensibility via Elisp.
Introduction
First of all: Emacs is not for everyone, and not for every task. In order to change a few characters in a textfile you are probably better off with a conventional editor like vim. Emacs is more like a multi-purpose development environment that you start in the morning and shut down in the evening, if at all.
Installation
Graphical and text-only versions exist, I strongly recommend the graphical version because of a lot of added features.
Getting Started
Without customization emacs is not better than any other editor. So in order to get started I suggest you grab yourself a .emacs. Here's mine: http://amd.co.at/fanopanic/dotemacs-0.0.2.tar.gz