This a text editor which has the option to save the content as a PDF document. It can also read existing .rtf documents and render them in the editor. These can then be saved as PDF there by providing a converter from RTF to PDF format.
<fo:editor /> will allow you to edit your XSL-FO mark-up and render it in various output formats. Users will be able to use their favorite renderers from the app with just the press of a button. Editing will be node-, code-, and wysiwyg-based.