Convert DocBook files to other formats (HTML, RTF, PS, man, PDF)

 The docbook-utils is a set of a few small programs intended to ease
 everyday use of technical documentation software and more generally use of
 SGML and XML.
 .
 Tasks they currently accomplish are:
  * jw: convert DocBook files to other formats (HTML, RTF, Postscript, PDF).
  * sgmldiff: detect the differences in markup between two SGML files.
  * docbook2man: converts a DocBook refentry to a man page.