The WFC software is divided in three parts of which this chapter deals with the first one: I - Read data from FOTs and store in FITS formatted files - extract data from all possible instrument modes and all relevant satellite information - Cleaning eventfiles from spurious and unwanted data - monitoring instrument behaviour by comprehensive logging and plotting - produce dead time data from housekeeping ratemeters - produce detector gain data from inflight calibration sources - create GTI files from selectable criteria - analyse pointing stability The other stages are mentioned briefly here: II - reconstruction of the sky image as viewed by the cameras - detection of Xray sources within the the field of view III - analysis of spectra and - analysis of lightcurves of sources