Cynthiune is a free software and romantic music player for GNUstep and Mac OS X. It can play MP3 and Ogg files.
DRM Dumpster uses a CD-RW and iTunes itself to convert all of your DRM music files to MP3 files that you can use with any music player.
krix is a visual music browser.
LAME is a library which allows some programs to encode MP3 files.
Max (Macintosh Audio for OS X)
Max (Macintosh Audio for OS X) is an application for ripping and encoding MP3 audio files. It aims to have a simple, intuitive interface. Features include: high-quality MP3 encoding using the LAME encoding engine, integration with FreeDB to automatically acquire artist and track names using libcddb, and output tagged with ID3v2.4 tags using TagLib.
(shareware) catalog, organize, sort and play MP3 files
XNJB is a Cocoa graphical user interface for Mac OS X for the Creative Nomad range of portable MP3 players and newer MTP players. It uses libnjb and libmtp for low-level device communication.