CIE published in 1974 its Publication CIE 13.2 Method of Measuring and Specifying Colour Rendering Properties of Light Sources. Publication CIE 13.3-1995 is an updated version of CIE 13.2, where typing errors were corrected and the terminology was updated. The software discussed in this leaflet and available as CIE D008-1995, Rel. 2.0 is based on the updated method of measuring colour rendering indices. It will produce results that agree - to the uncertainty of rounding the last digits - with results calculated on the basis of CIE 13.3-1995. The programs CIE13_3w.exe and CIE13_3d.exe are computer based tools for specifying colour rendering properties of light sources. The programs calculate, according to the rules described in CIE 13.3-1995, the light source chromaticity co-ordinates, the correlated colour temperature, the 14 special colour rendering indices and the general colour rendering index, using the first 8 CIE test colour samples. The program allows the use of other test colour samples as well. The program CIE13_3w.exe runs in a Windows environment (version 3.0 or higher). CIE13_3d.exe is the same program running under DOS. Both programs include options to save the results in a file and to print them. CIE13_3w has built in clipboard facilities to transfer data directly to word processors, spread-sheet applications or other Windows programs. Although every effort was taken to ensure that no error is contained in the disk, this disk is not an official CIE endorsed publication.