Ecasound is a software package designed for multitrack audio processing. It can be used for simple tasks like audio playback, recording, and format conversions, as well as for multitrack effect processing, mixing, recording and signal recycling. It supports a wide range of audio inputs, outputs, and effect algorithms. Effects and audio objects can be combined in various ways, and their parameters can be controlled by operator objects like oscillators and MIDI-CCs. A versatile console-mode user interface is included in the package.
cmus is a small, fast, and powerful console music player for Linux and *BSD. It supports almost all common file formats, SHOUTcast/Icecast streaming, and multiple output plugins. cmus features multiple media library views, a playqueue, a directory browser, powerful filters, and vi-style search and keybindings. It also features gapless playback, ReplayGain, Unicode support, and customizable color schemes.
Herrie is a command line music player. It has a split-screen file manager and playlist interface and supports a number of file formats (MP3, Ogg Vorbis, wave, FLAC, etc). It also has some nice features, including a chroot() function for untrusted setups (remote logins, parties, etc). AudioScrobbler is also implemented using Curl.
Plait (pronounced "play") is a command-line jukebox and music player front end. It understands brief, easy to type queries that pick a single song, mix queries that combine works from multiple artists, and stream queries that find Shoutcast radio streams. A variety of filters are available to pick just the music you want to hear. In order to actually play the music it finds, Plait automatically hands off a playlist to one of the supported music players, or creates a playlist that you can manually load.