TeX is an extremely powerful macro-based computer text formatter written by Donald E. Knuth, very popular in the computer-science community. Knuth began TeX because he had become annoyed at the declining quality of the typesetting in volumes I--III of his monumental `Art of Computer Programming'. In a manifestation of the typical hackish urge to solve the problem at hand once and for all, he began to design his own typesetting language. He thought he would finish it on his sabbatical in 1978; he was wrong by only about 8 years. The language was finally frozen around 1985. Though well-written, TeX is so large (and so full of cutting edge technique) that it is said to have unearthed at least one bug in every Pascal it has been compiled with. Research TeX