We wish to thank current active contributors to PSPP:

* Ben Pfaff wrote the initial program and manual, which comprises the
majority of the current code. Ben continues to contribute and 
most of the core libraries which ensure that PSPP runs with optimal
speed are his work.

* John Darrington wrote the initial version of the graphical user interface,
and many of the statistical procedures.  John also implemented support for
long variable names, PostgreSQL and Gnumeric and made numerous
revisions to other modules.

* Jason Stover contributed statistical and numerical functionality,
including lib/gslextras and the linear regression features. Jason 
is also an important contributor to GSL, which is used by PSPP. 

* Mehmet Hakan Satman provided the initial implementation of the QUICK CLUSTER command.
  Alan Mead and others contributed later improvements including the cluster membership subcommands.

* Friedrich Beckmann wrote the GRAPH command.

We also thank past contributors:

* John Williams wrote an initial draft of the T-TEST procedure.

* Michael Kiefte contributed bug fixes and other enhancements.

* Patrick Kobly contributed bug fixes and other enhancements.

* Rob van Son wrote the original version of the routine for
  calculation of the significance of the Wilcoxon matched pairs signed
  rank statistic used by the NPAR TEST command.