nicEdit is a very lightweight wysiwyg HTML editor, distributed under the MIT license (which means that as long as the copyright info remains intact, you can do pretty much anything with it, including distribute it with a commercial application). There are a couple of drawbacks to nicEdit - first, it does not produce standards compliant HTML. If it did, it would not be anywhere near as lightweight, so that's a bit of a tradeoff (it relies on the browser's own HTML editing features, so if you use a decent browser you should get pretty good results). The other main problem I found though, is that if you have a form containing a nicEdit editor, and submit the form using Javascript ie. form.submit(), the content of the editor is not posted back to the server!

If you would like to know why that is, and what you can do about it, read on...