I've made Edwood understand Markdown. Toggles between rendered view and straight text, and supports direct editing in the markdown view, including **text** to bold, etc. Not perfect, but you have the escape hatch of looking at the text.
Certainly still buggy, but now my daily driver. Don't read the code, a machine wrote it and I've only lightly audited it.
Available at https://github.com/paul-lalonde/edwood