Philip Hazel

Philip Hazel is a computer programmer best known for writing the Exim mail transport agent and the PCRE regular expression library. He was employed by the University of Cambridge Computing Service until he retired at the end of September 2007. In 2009 Philip wrote an autobiographical memoir about his computing career.

Philip Hazel is also known for his typesetting software, in particular "Philip's Music Writer", as well as programs to turn a simple markup into a subset of DocBook XML for use in the Exim manual, and to produce PostScript from this XML.

...
Wikipedia