Javascript – Any javascript (web-based) wysiwyg editor that produces xsl:fo

I am having a hard time finding on OSS or commercial web-based (javascript) WYSIWYG* editor that produces XSL:FO. Would I would love to have the editor capable of doing…

• The user is presented with common text-editor interface, not unlike the editor I am currently typing into to submit this question to SO.
• The user is able to define all the structural components afforded by XSL:FO (new pages, new regions). Any "simplification" the editor can do (such as handling some of the implicit XSL:FO formatting necessary to place graphics and the like) would be helpful
• Ability to create inline areas, such as lists and tables, add graphics, etc
• Ability to style within the confines of the XSL:FO specification

(*) Since it is a WYSIWYG editor, there must be an ability to preview the document being created. Since XSL:FO requires an XLS:FO processor to translate into documents (RTF, PDF, etc etc) I would expect there to be a means to select which document type I would like to render, select "preview", and that document be rendered for preview (in an iframe, another window, whatever). I would expect this to require a server-side XSL:FO processor component as well. A bonus would be a "default" auto-preview that sends an AJAX request to the server to update the preview during a users content-creation "pause" (if the user doesn't add content for 5 seconds, auto-preview).