Substrate

With his students, he was able to write a program capable of typesetting the entire 700-page revised volume of his book by 1978. The program, called TeX, revolutionized how scientific papers are formatted and printed. It’s also one of the oldest OSS projects still in use. The disconnect between technical or scientific and nontechnical authors is also fundamental to understanding TeX’s mainstream obscurity: In nontechnical publishing, typesetting is usually not essential for conveying the author’s intent. Typesetting is considered ornamental; authors of popular material are content to send a Word document to their publisher and let professionals do the rest. Technical authors, on the other hand, need to convey their meaning precisely through glyphs, sizes, and placement. TeX lets them do that, as well as exchange their documents in a widely understood format.