Just saying, sites like these are also pretty great for accessibility, screen reader users in particular.
I think this one would be slightly better if it rendered that Markdown as simple HTML if accessed through a real browser, but I can imagine even this version being pretty useful.
I think it could also make the "Small web" crowd pretty happy too.
Amen to that. It's funny how virtues like accessibility and good API design matter just as much as ever in this new era. Good ideas don't go out of style.