Off-line analysis of x-ray data within IRAF PROS The Post-Reduction Off-line Software (PROS) is a portable x-ray analysis software system designed to run under NOAO's Image Reduction and Analysis Facility (IRAF) The PROS system provides IRAF users with tasks that will properly access the x-ray data. In particular, it supplies the tools to take into account the additional parameters peculiar to x-ray imaging data (photon energy and time information may be retained in x-ray images, along with positions), and algorithms for a correct treatment of the errors, based on photon counting statistics. Version 2.5.p1 March, 1998 To use the packages first start IRAF using the 'cl' command and at the 'cl>' prompt type 'xray'. Extensive online documentation is available on the Web at: http://hea-www.harvard.edu/PROS/PUG/PUG2.html The PROS User's Manual is available in two different forms: Postscript files at the IRA web address Manuals in room 307 Contact Person: F.Tinarelli tinarelli@ira.inaf.it