TeX , by Donald E. Knuth, is a computer type-setting system and markup language that heralded a revolution in the quality of the vast majority of published mathematics.
- The ideal is to be able to describe important classes of documents in terms of their components, without mentioning actual fonts or point sizes or details of spacing; a single style-independent document can then be set in many different styles.
- -- Donald Knuth, The TeXbook .
- write TeX Tcl-style
- a lightweight clone of (a subset of) LaTeX, aimed at producing formula rendering for web pages and the like. It does not depend on having TeX or its fonts available.
- a text editor/IDE designed to make editing TeX documents easier.
TeX is mostly used via LaTeX, which is built on top of it.