A typesetting system
based on the TeX
programming language developed by Donald E. Knuth. Most people who use TeX, however, utilize one of several macro packages that provide an easier interface. The two most popular are LaTeX,
originally written by Leslie Lamport, and plain TeX,
written by Knuth. LaTeX provides higher-level macros, which makes it easier to format documents but sacrifices some of the flexibility of TeX.