Whizzywing
Whizzywing is a really small (7k compressed), blisteringly fast WYSIWYG editor with enough basic features to meet most needs: headings, lists, blockquotes, tables, links, text-wrapped images, bold, italic, underline, delete, sub- and super-script. Only one file is needed. Include the JavaScript file and either add a class to elements you want to turn into an editor, or switch on and off with a single call. The toolbar is uncluttered with only a few items, using dropdown menus to choose formatting. Yet the functionality can easily be extended to add your own commands and features. Whizzywing won't confuse your users with HTML or technical terms like href, vspace, target, etc. but there is an option to edit the HTML source directly. Whizzywing preserves manual changes to the source and outputs sane, cross-browser, HTML which won't be littered with useless classes or spans.