TeX

TeX (/tɛx/), stylized as TeX, is a free and open source software typesetting program that was designed and written by computer scientist and Stanford University professor Donald Knuth[2] and first released in 1978. The term now refers to the system of extensions – which includes software programs called TeX engines, sets of TeX macros, and packages which provide extra typesetting functionality – built around the original TeX language. TeX is a popular means of typesetting complex mathematical formulae; it has been noted as one of the most sophisticated digital typographical systems.[3] https://en.wikipedia.org/wiki/TeX