Don't know about RTF, but maybe you can use the DHTML Editing Component that comes with Internet Explorer 5. It edits HTML, not RTF, but lets you apply all the format.
I haven't used it from a web page but from a VFP form, but the control is actually more oriented to your case. The main problem is that documentation is not very good. You can check it at MSDN (search for DHTML Editing Component and the DOM model). If you want to try it, just add it to the VFP Activex Controls list and drop it into a form.
Good luck!
>Anyone know how to allow web user to input data in RTF (Rich Text) format? User should be able to input text, select font, size, style (bold, italics) and bullets.