``The HKL suite is a package of programs intended for the analysis of X-ray diffraction data collected from single crystals, and consists of three programs: XdisplayF for visualization of the diffraction pattern, Denzo for data reduction and integration, and Scalepack for the merging and scaling of intensities obtained by Denzo or other programs.'' [, page 3] It is written by Zbysek Otwinowski and Wladek Minor.
Bound copies of THE HKL MANUAL are available on site. More information can be found at the HKL Research, Inc. site. The Molecular Structure Corporation has some documentation for denzo at http://www.msc.com/docs/denzo/. Documentation can also be obtained by typing denzodoc at the unix prompt.