http://www.xstandard.com/
The editor generates clean XHTML Strict or 1.1, and uses CSS for formatting, to ensure the clean separation of content from presentation. The editor is keyboard accessible, and markup generated by XStandard meets the most demanding accessibility requirements. The editor's cool features include drag & drop file upload, spell checking and an image library that integrates tightly with your CMS.
хотя кто знает - надо попробовать =)