Software is described that converts single-crystal diffractometer output files as produced by manufacturers' software into a standardized instrument-independent form consisting of a clear, complete, well documented record of the sample and the diffraction measurements performed upon it. Information not already available in the manufacturers' diffractometer files is obtained in an interactive question- and-answer session. The software is written in a modular way. Available modules can deal with Enraf-Nonius CAD-4, Philips PW1100 and Siemens P21 single-crystal diffractometers and produce output in CIF or SCFS format.