Redactor - WYSIWYG editor on jQuery
If you're looking for a Rich Text Editor, this is the only one I will recommend. I wrote a proprietary RTE last year and continue to maintain it because nothing available both worked and produced clean markup. Redactor came out this spring and is the only generally available RTE that does this. If you insist on OSS, WYSIHTML5 is the best available.<p>For those that care, Redactor uses the designMode technique, leans on the browser for most operations and keeps the markup clean via regexp cleanup. This is the cleanest solution for the most common use case of html email/html item entry. The other two techniques are full emulation and contenteditable.<p>Google uses full emulation in their products. You type into a hidden text field and the display/selection/cursor is entirely script rendered. This is especially good for things like docs where they need to emulate word's behavior. Downside is that doing it is a lot of code and it's easy to miss OS specific keybinds (e.g. CMD+left/right in OS X don't work in gmail).<p>Using contenteditable would be the preferred technique but it's buggy as hell. Of the editors I know about only Aloha and my editor take this approach. The amount of code is relatively small (mine is around 2k sloc) but it's all really ugly code that reminds me of the bad old days in 2002-2004 when I had my own DOM abstraction lib.