I have a very heavy involvement in genealogy and collect a significant amount of duplicate information in photos, files and programs.
FolderMatch is by far the best software I have found-it finds gigabytes of diskspace taken up with duplicates and safely allows me to store them in a separate file for later filtering before I permanently and securely delete large volumes of duplicates, triplicates and, at times, quadruplicates.
A very fast, secure and efficient way of clearing up diskspace.
Congrats to the developers of FolderMatch, you save me a lot of time and a huge amount of space, both of which I have very little of.