Good article, but I couldn't help stumbling over the thumbnail history of markup languages in the introduction -- in particular the assertion that Markdown, "in

Good article, but I couldn't help stumbling over the thumbnail history of markup languages in the introduction -- in particular the assertion that Markdown, "in 2004 ... really pushed the concept over the brink of ubiquitousness". I would say that the concept of markup languages truly became ubiquitous in the 1990s, with the extremely widespread popularity of a markup language that the author didn't even mention -- the Hypertext Markup Language.