RipIT is a command line program for ripping, encoding, and tagging MP3s that needs no user intervention. It is a wrapper for dagrab, cdparanoia, cdda2wav, LAME, Ogg Vorbis, Flac, Faac, Musepack, Wavpack, mp4als and ffmpeg. It supports the retrieval and submission of CDDB and MusicBrainz entries and cover art.
Quicktime for Linux lets you read and write Quicktime movies using several codecs. There are many Quicktime libraries for Linux; this one emphasizes reliability and accuracy while not stressing economy. Also included are frontends to several of the codecs which don't require Quicktime encapsulation, header dump, chunk extraction, and recovery tools.
libsndfile is a C library for reading and writing sound files such as AIFF, AU, WAV, and others through one standard interface. It can currently read/write 8, 16, 24 and 32-bit PCM files as well as 32 and 64-bit floating point WAV files and a number of compressed formats. It compiles and runs on *nix, MacOS, and Win32.
MP3Info is an MP3 technical info viewer and ID3 1.x tag editor. It has an interactive mode (using curses) and a command line mode. A separate executable includes a GTK-based GUI version. MP3Info can display ID3 tag information as well as various technical aspects of an MP3 file including playing time, bit-rate, sampling frequency, and other attributes. It can output this information in a pre-defined or user-specified format.
The Snack sound extension adds commands for sound play/record and sound visualization, e.g. waveforms and spectrograms. It supports in- memory sound objects, file based audio, streaming audio, WAV, AU, AIFF, and MP3 file formats, synchronous and asynchronous playback. The visualization canvas item types update in real-time and can output postscript. New commands and file formats can be added using the Snack C-API.
mp3tools is a set of utilities (mp3id3, mp3info, mp3index, and mp3gui) for managing collections of MPEG audio files. It can get information such as bitrate and play length about a file, view and alter ID3 tags, and generate completely customized listings. All of these functions can be done either from the command line or a GUI.
Mixer.app is a mixer utility for Linux/FreeBSD systems. It is designed to be docked in Window Maker. This utility has three volume controllers that can be configured to handle any sound source, the default sources are master-, cd- and pcm-volume. Sound sources can easily be muted and there is also wheel mouse support.
aRts is a framework for developing modular multimedia applications. The sound server, artsd, allows multiple applications to cooperatively process and output sound and music. aRts is designed to provide its filter and synthesis capabilities to other applications using the multimedia communication protocol (MCOP). aRts is also capable of modular realtime synthesis. It can create sounds & music (realtime midi synthesis) using small modules like oscillators for creating waveforms, various filters, mixers, faders, etc.
GNU xhippo is a simple GTK-based playlist manager, designed to play music using mpg123, xmp, or most other commandline-based players while providing a friendly, clean X interface. It is localised in both English and German. Its interface is based upon the Amiga program HippoPlayer. It supports drag-and-drop, has optional GNOME support, and has a simple text-based playlist format compatible with many other players.