Nano

nano is a text editor, like vi or emacs, but less arcane for the newbie. Probably as close as you're going to get (in a text-only editor) to the hot-key combination in other GUI-driven editors (ie, control-Q for quit, etc.) nano is basically an updated pico and replaces/replaced pico on many systems that have/had it. Since the key combinations are visible at the bottom of whatever screen you're on, all you really need to know is that the caret (the ^ character) means "press the control key at the same time as the other letter".

See also vi, ee (commonly aliased under FreeBSD as "edit"), joe, nano, pico or emacs.