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.
AudioSlicer is a Cocoa GUI application that finds all silences in an audio file and allows you to split it into several smaller audio files and to name/tag them properly. While most other tools split automatically according to certain criteria, AudioSlicer shows you all silences within a certain range of duration. You can then listen and decide whether you want to split there. The splitting is done without loss; there is no decoding and re-encoding of audio data.
Find Duplicate Music Files detects music files that contain the same music, even if the files are differently named, and are in different formats such as MP3, OGG, WAV, WMA, M4A, and RealAudio and contain different or non-existent meta-information such as ID3 tags. The program operates on whole directories of music files, analyzes them, and outputs the filenames of pairs that seem similar, based on their audio fingerprint or perceptual hash.
QtOIDUA is a graphical user interface for OIDUA, an Audiolist clone that generates lists of audio files based on their location in a directory tree. It supports all features of OIDUA, and makes it easy to create fields, add directories, choose colors, and set options. Users can even save list configuration files so that they can easily recreate any previously created list.
Transcribe! is an assistant for working out a piece of music from a recording. It offers many features aimed at making the transcription job smoother and easier, including the ability to slow down the music without changing its pitch, and to analyse chords and show you what notes are present.
CLAM is a multiplatform software framework for research and application development for the Audio and Music domains. It offers a conceptual model for building systems as well as tools for the analysis, synthesis, and transformation of audio signals using high level representation (notes, spectral peaks, etc.). It also provides multiplatform system abstraction and tools for audio and MIDI file handling, device handling, GUI and XML support, and more. It has proper Linux audio architecture integration (Ladspa, Alsa, OSC, Jack, VST, etc.) and rapid graphical prototyping both for the processing core and the user interface (Qt designer integration).
MARF is a general cross-platform framework with a collection of algorithms for audio (voice, speech, and sound) and natural language text analysis and recognition, along with sample applications (identification, NLP, etc.) of its use. MARF can run distributed over the network (CORBA, Java RMI, and Java XML-RPC Web Services) and may act as a library in applications or be used as a source for learning and extension.