Mixxx is software for DJs that provides everything needed to create live mixes. It allows you to beatmatch songs and crossfade them together, like you would with turntables and a mixer. It runs without any extra hardware, and offers a wide range of advanced features including comprehensive MIDI controller and vinyl control support. To obtain the lowest latency and highest responsiveness, it uses hardware video acceleration and takes advantage of multi-core CPUs.
DR14 T.meter is a commandline tool for computing the Dynamic Range of your music according to the procedure used in the offline meter released by the Pleasurize Music Foundation. It is very useful to measure how loud your music is and to understand that a good quality album always has a good dynamic. It's also useful for understanding the effects of the so-called loudness war.
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.
Mp3blaster is an interactive text-based program that plays several audio file types (MP3, Ogg Vorbis, wav, and sid). It is one of the few audio players for the text console that allows full interactive control during playback. One of its key features is the ability to compose a very flexible playlist (while playing!). It plays most MP3 formats and has full mixer support built in.
xmms-crossfade is an output plugin for XMMS. Its main feature is automatic crossfading. It also removes the gaps between tracks, to play whole MP3 albums without any audible interruption. xmms-crossfade supports OSS via a builtin driver, and any other platform by using existing output plugins. As of version 0.3.9, the Audacious media player is also supported.
Streamripper records MP3, Ogg, AAC, and NSV audio and video files from Shoutcast and Icecast compatible streams. The streams can be recorded as a whole or in individual tracks. Streamripper also features a relay stream, which lets you listen or watch live from multiple clients while recording.
Quod Libet is a music library management program. Rather than categorize songs by genre, artist, and album, it lets you search and display them however you want. It supports regexp-based searches, album cover display, tag editing, ReplayGain, multimedia keys, and an OSD. Also included is Ex Falso, a tag editor that has the same editing features found in Quod Libet, but does not play audio files.
abcde is a frontend to cdparanoia, wget, cd-discid, id3, and your favorite Ogg Vorbis (the default), MP3, FLAC, Ogg Speex, or MPP (Musepack) encoder. It grabs an entire CD and converts each track to the desired format, then comments or ID3-tags each file, all with one command. It supports multiple output in a single CD read, the creation of a single track from a CD, resume operation, CD concatenation, volume normalization, gapless encoding (with LAME), parallelization, SMP, proxies, customizable filename organization and munging, playlist generation, distributed encoding via distmp3, and more.