Judging by some of the replies I’m seeing, some clarifications matter:
1. This is incoming formatting only, not composing (for now).
2. It’s not really markdown-specific, that’s just the way it was being tested.
3. Only a limited selection of rich test is being enabled. It’s not going to support colors, layout changes, fonts, size changes etc.
(IMO the ones they chose will improve readability.)
4. A number of other Fediverse platforms already support these!
Funny to think:
Newsgroups and early mailing lists were all plaintext, so people came up with conventions like using asterisks and underscores.
Web forums were able to display rich text, and they used markup to implement it.
Early social media like LiveJournal and such supported rich text via raw HTML
Twitter was designed to fit in an SMS message, so it was plain text.
And everyone went back to using asterisks and underscores. Plus abusing Unicode lookalike chars.