This is really a brief history of HTML / XHMTL. Markup goes back long before either. In 1980-81 I used Brian Reid's SCRIBE formatting program (and Emacs as the text editor) to produce the manuscript of my law review note. According to Wikipedia, Brian won the ACM's Grace Murray Hopper Award for his dissertation, which was based on SCRIBE -- which itself was based on (and was the first robust version of) RUNOFF. See http://en.wikipedia.org/wiki/Scribe_(markup_language).
Fond memories of editing Scribe the night before some deadline, the load on TOPS-C getting higher, and suddenly the message %DECSYSTEM-20 NOT RUNNING. One moment of quiet in the terminal room, then everyone cursing and wailing.