Audacity is a cross-platform multitrack audio editor. It allows you to record sounds directly or to import Ogg, WAV, AIFF, AU, IRCAM, or MP3 files. It features a few simple effects, all of the editing features you should need, and unlimited undo. The audio I/O uses PortAudio, which fully supports OSS, Mac OS X CoreAudio, and Windows WMME, and can be compiled with support for ALSA and Jack.
Audiality is a highly scalable and portable audio engine and synthesizer. MIDI files are used in combination with scripting and modular synthesis, to minimize file sizes and maximize flexibility. Audiality can be used as a music and sound effects player in multimedia productions, or as a realtime MIDI synthesizer.
Audio::Xmpcr is a Perl API to the XM PCR Satellite radio. It offers two different operating modes (direct and remote+daemon) via a single interface, continuous device polling for instant, accurate song listings, auto notification when songs change on any channel, and a few utility programs including a Web interface for remote control/listening to the radio via icecast, a stream ripper that divides songs up into properly-named wav files (for making MP3s), and a finder that searches channels for the song(s) wanted, and records just those.
Aurion Music Manager (AMM) has been designed to be a very user-friendly interface for using mpg123, cdrecord, mkisofs, lame, and other very powerful command-line music tools. It uses the SDL for its graphics, and the interface can use the TV output capability featured by several video cards. AMM also includes a WAV file player, called pwav123.