Where TEX comes from
Donald Knuth wrote TeX between 1977 and 1982 because he was unwilling to accept the typographic quality of his own book's second edition. Leslie Lamport's LaTeX, released in 1984, added the document structure that made it usable by people who did not want to program a typesetter. Four decades on, essentially every mathematics, physics and computer-science journal accepts — often requires — LaTeX, and arXiv stores submissions as source.