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.
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.
KPlaylistCreator is a jukebox for KDE. It scans for MP3 and Ogg Vorbis files, located in various directories, creates a unique tree view with genre, artist, album, and song title information, features a user rates mechanism, a user playlist manager, and a wizard playlist creator, edits tags for both MP3 (ID3 v2) and Ogg Vorbis files, checks directories for new and missing files automatically, sends playlists to a directory, XMMS, or to K3B, displays and sets the album art of MP3 files, creates playlists from a virtual library, and includes popup windows to indicate change of song.
Music Manager is a Konqueror plugin that lets you standardize the filenames of your music files, guess information and set ID3 tags from the file's name (this can be done to several files in one shot), rename many selected files based on their ID3 tags, set ID3 tags in mass for selected files with options for copying ID3s from other files and leaving some ID3 fields untouched, rename _ to space and vice versa, create HTML and text indexes of your collections (including total playing time, etc., configurable through templates), create nice CD covers with full listings of your music files (also configurable through templates), and organize your music collection to create a CD.