Free WYSIWYG editor. I have used this a couple of times on various projects.
TinyMCE - Free WYSIWYG editor
TinyMCE has been around for a long time as a full featured "what you see is what you get editor". It's been a few years since I have used it, so I think it's time to check it out again. Somewhere there was a reference to the release of a cloud based version with additional features. I hope there is still a free community version.