dupeGuru is an Open Source, cross-platform GUI tool designed for finding duplicate files.
It is meant for finding duplicate files on your computer by either scanning filenames or contents. The filename scan features a fuzzy matching algorithm capable of locating and displaying duplicate filenames even when they do not perfectly match.
dupeGuru works well with music files due to its special Music mode that scans tags. It then displays music-specific information from its duplicate results window. It also works with picture files implementing a similar fuzzy algorithm to locate images that may not be the same but relatively close.
dupeGuru permits you to tweak its matching engine tailoring it to find a specific type of duplicate file. dupeGuru has a preference page in the help file that lists the different scanning engine settings you have available for modification. Additionally, as a safeguard, dupeGuru's reference directory system, as well as its grouping system, will prevent you from accidentally deleting files.