Sonic Visualiser is an application for viewing and analysing the contents of music audio files, containing advanced waveform and spectrogram viewers as well as editors for many sorts of audio annotations. It supports sophisticated audio selection, looping, and playback features, as well as the Vamp audio feature extraction plugin format.
somaplayer is music player for MP3, Ogg, wav, audio CDs, MP3 streams, and Ogg streams. It is able to use the appropriate sound drivers or demons or to stream directly to an Icecast server (Icecast2 or SHOUTcast) or to encode in MP3 and Ogg Vorbis. It also acts as a sound daemon that is able to accept connections from other somaplayers or any other sound player (xmms, mpg123, and others) thanks to a special wrapper.
Open Sound World (OSW) is a scalable, extensible programming environment that allows musicians, sound designers, and researchers to process sound in response to expressive real-time control. It combines a familiar visual patching paradigm with solid programming language features such as a strong type system and hierarchical name spaces. OSW also includes an intuitive model for specifying new components using a graphical interface and high-level C++ expressions, making it easy to develop and share new music and signal processing algorithms.
FMS is a tool to create all kinds of sounds from scratch. You can play any sound (sine, triangular, vowels, etc.) with any property settings (frequency, volume, balance, sweep, etc.) and modulations thereof. It also features tools to save sounds, play .MUS music, graphically display sounds, and make real noise.
The MusicBrainz client library (also known as mb_client or libmusicbrainz) is a library for developers that wish to add MusicBrainz metadata lookup capabilities to their applications. It calculates CD Index IDs and Relatable's acoustic fingerprints, and looks up the metadata associated with the calculated IDs.