> TeX, which is an equally monumental if not greater achievement.
TeX didn't come out of nowhere. It's a successor to the macro-based document formatting system which began with RUNOFF and went through roff, nroff, tbl, eqn, MM, troff, ditroff, and groff. The last remaining usage of those tools seems to be UNIX-type manual pages. There was so much cruft a restart was required.
Linotype didn’t come out of nowhere either. Printers used to cast type manually.
And don’t just gloss over TeX’s astounding correctness. It’s a truly remarkable feat of the human intellect to design something so large with so few errors.
For those who haven't seen Knuth's own analysis of his errors while writing TeX, it's well worth reading his 1989 article "The Errors of TeX" [1] and glancing through the full chronological list of errors [2].
TeX didn't come out of nowhere. It's a successor to the macro-based document formatting system which began with RUNOFF and went through roff, nroff, tbl, eqn, MM, troff, ditroff, and groff. The last remaining usage of those tools seems to be UNIX-type manual pages. There was so much cruft a restart was required.