X-raycrystallographers depend on software to process and analyze their data. These programswere often developed withemphasis on mathematical algorithms rather than inputand outputcontrol. As a result, these programs can be difficult to set up. This paperdiscusses a specific dataprocessing program, scaling, which is the laststep in crystallographydataprocessing. It computesthe scalefactors for the different X-rayimages and merges them to obtain a list ofthe Braggreflection intensities.