Best CSS gradient, shadow, radius, transition and transform WYSIWYG editor I’ve seen to date. You can create instances for :hover, :active, custom class states. You can also work with transitions and transforms.
FROONT seems to be worth playing with.
Jetstrap may be useful.
Via @jakubspanihel
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