""Github Flavored Markdown" is a thing, has been for a very long time. Not a peep from Gruber about it."

In the podcast John Gruber did with Marco Arment ( https://overcast.fm/podcasts/episode/344902019595#t=4527 ), John Gruber notes "Github Flavoured Markdown" is a good product name.

He also says that they should standardise using a different name.