Prose.io has kind of a hybrid markdown editor (I think it's WYSIWYM?). It has markdown syntax highlighting that happens to look similar to the final output, th

Prose.io has kind of a hybrid markdown editor (I think it's WYSIWYM?). It has markdown syntax highlighting that happens to look similar to the final output, though the markdown tags are still displayed. They also have a toolbar, which is used like a regular WYSIWYG toolbar, but generates mardown tags. It's pretty neat.