I wouldn't like to force the author to know html. HTMLArea looks very promising. It is cross browser compatible, supported by a company, GPL and very advanced
http://dynarch.com/htmlarea/I also found the following document interesting: http://www.morphon.com/xmleditor/tutorials1.shtml#d0e141
I am not necessarily sure of how to save it in the db so that it can easily be imported/exported into all kind of different formats and applications.
