Metamorphose File -n- Folder Renamer is a free, open source mass renaming program that combines great flexibility with an intuitive interface. Allows many command line renaming operations in a single utility, perfect for those of us that need to rename large numbers of files and/or folders on a regular basis.
Renames files and folders at the same time.
Preview every item to be renamed before comiting changes.
Load all files in directory and in subdirectories (recursive renaming).
Undo renaming operation in case of mistakes.
Filter items to rename by regular expression.
Rename MP3 files according to their ID3 tags.
Full unicode support means any character from any language can be used.
Use of all allowed characters under Windows and OSX, all except ':' in Linux.