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.
Virtual Sound provides unlimited effects and modulation for sophisticated audio generation, with unique instrument simulation capabilities to craft your own unique soundscapes. All effects are parametrized and their parameters may be controlled through the outputs of other effects, through samples, or through special modulators. Instrument simulation is based on recursively-linked filter networks. Actual instruments can also be simulated through the statistical learning library incorporated in VSound.
Thinksynth is a modular synthesizer. It uses the JACK Audio Connection Kit for sound input and output, and ALSA for MIDI processing. Instruments are created with .dsp files, which define a network of Thinksynth modules using a simple interpreted language. A collection of example .dsp files is available in the source distribution.
Cecilia is a graphic user interface for the sound synthesis and sound processing package CSound. Cecilia enables the user to quickly build graphic interfaces with sliders and curves to control CSound intruments. It is also an editor to CSound with syntax highlighting and a built-in reference.
WaveSurfer is a sound visualization/manipulation tool for novice and advanced users, with a simple and intuitive user interface. It can be adapted to different tasks, such as speech research and education, speech/sound analysis, and sound annotation/transcription. You can also make more advanced/specialized applications by extending it with custom plugins or embed WaveSurfer components in other applications. Its flexible interface handles many different file formats, and it runs on many flavors of Windows and Unix. It also supports encoding and Unicode with unlimited file size, and more.
Soundtank is a program that hosts musical instruments for you to play; each instrument can be controlled via MIDI. You can create custom instruments and save them to files, and can also load instruments that other people create. It relies on LADSA plugins, as it has no built-in sound synthesis algorithms, but hosts them in "realtime objects" which embody the structure of the audio signal flow. RTObjects can be controlled in a completely customizable fashion using MIDI events sent through the ALSA sequencer interface. Soundtank outputs audio through ALSA or JACK.