These programs are used to compare runs from different environments. Differences in floating point numbers are ignored if sufficiently small, where sufficiently small can be defined in a configuration file which can change the rules depending on the context. If you wish to download this software for checking codes on this site and only for this purpose, you can check "Research making comparisons with other codes of this type" when indicating the type of use.
This software is part of the MATH77/mathc90 collection here.