Markdown the specification and Markdown the Perl script came out in March 2004 [0] and were last updated in December [1] the same year. I think it's fair to assume that John Gruber considers it perfected for the use case he had in mind.

Any further evolution of the language is now up to anyone who cares to implement a processor. There is nobody maintaining the language itself.

I absolutely agree that it is pretty useless for anything bigger than a small README without resorting to HTML, but I don't think that's a big problem, and I don't think it makes Markdown meaningless. I used to write documentation in HTML, and I think replacing 95% of the HTML with Markdown makes it much nicer to work with.

I wouldn't write a book in HTML, but there are those that have, using CSS3 print styling!

Before hearing your argument, If I were hypothetically to ever write a book, I would likely not even consider anything but LaTeX. But thanks to your episode, and you simply reminding me that DocBook is still out there, I might spare DocBook a look first. It was a good episode and your points are all valid. Thanks!

[0] https://daringfireball.net/2004/03/introducing_markdown

[1] https://daringfireball.net/projects/markdown/