stylistic:style_transfer, structural:summarization, quality:correction
Literate programming

While developing TeX, Knuth created a new methodology of programming, which he called literate programming, because he believed that programmers should think of programs as works of literature:

Instead of imagining that our main task is to instruct a computer what to do, let us concentrate rather on explaining to human beings what we want a computer to do.

Knuth embodied the idea of literate programming in the WEB system. The same WEB source is used to weave a TeX file, and to tangle a Pascal source file. These in their turn produce a readable description of the program and an executable binary respectively. A later iteration of the system, CWEB, replaces Pascal with C, C++, and Java.

Knuth used WEB to program TeX and METAFONT, and published both programs as books, both originally published the same year: TeX: The Program (1986); and METAFONT: The Program (1986). Around the same time, LaTeX, the now-widely adopted macro package based on TeX, was first developed by Leslie Lamport, who later published its first user manual in 1986.