Simple Text Editors

(this list isn't complete, by far)

What we need of a simple text editor is automatic indentation. Any text editor is capable of this, basically. Even nano, the tiniest, command line text editor.

Atutomatic indentation means, you add 3 indents and start typing,
add new line (press Enter)
type on...
add new line...
and each line will still be at "indent 4" (at this distance from the left margin).
I call this "lane 4".

Then you press tab...
press it twice...
and you'll be in "lane 5" :)
i.e. 5 indents from the left margin.
You'll remain here, in this "lane", until you change it...
THis is very-very comfortable!

And... this is practically all that you need of a simple text editor! :)
(One other thing is to be able to add or remove indent to / from selected text block, but this usually comes with auto-indentation.) The conventional basic method is to press tab or (to remove indent) press shit + tab.