WYSIHTML5 – A Better Approach to Rich Text Editing
wysihtml5 is an open source rich text editor based on HTML5 technology and the progressive-enhancement approach. It uses a sophisticated security concept and aims to generate fully valid HTML5 markup by preventing unmaintainable tag soups and inline styles.
Via @ViliamKopecky
I very like this one http://jejacks0n.github.com/mercury/
@Robin Bortlík: Thanks for sharing, that really looks nice. Bookmarked it.