a library for reading and editing the meta-data of several popular audio formats. Currently it supports both ID3v1 and ID3v2 for MP3 files, Ogg Vorbis comments and ID3 tags and Vorbis comments in FLAC files.
A bit more feature powered than Zamzar. With more formats and a bit more complicated interface. However, I can guarantee you that it’s worth the usage. No email needed. 100Mb limit