GUC is a unit converter that was ported from scratch from the PalmOS YAUC to GTK for the YOPY. It contains most of the more useful conversions, but certainly not the whole collection.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.