The first versions of Denzo and Scalepack were written by Zbyszek Otwinowski at the University of Chicago in 1983 and, after 1988, at Yale University.
The program XdisplayF was developed by Wladek Minor at Purdue University, and, since 1995, at the University of Virginia.
Currently, components of the HKL and the HKL-2000 packages have been developed in Zbyszek Otwinowski's lab at the University of Texas, Southwestern Medical Center at Dallas and in Wladek Minor's lab at the University of Virginia in Charlottesville.