gsyn is internally designed to be an extensible, modular synthesizer, but the interface and current codebase present a Roland TB-303 emulator which is programmed using fasttracker-style note entry. It also features delay reverb and distortion, so the sound is comparable to Propellerhead's ReBirth RB-338. gsyn has been compiled and tested under Linux 2., IRIX 6.2, Solaris 2.6, Windows 95, and Windows NT.
jMusic provides a library of classes for generating and manipulating music, and is a solid framework for computer assisted composition in Java. jMusic supports composers by providing a music data structure based upon note/sound events, and methods for working with that musical data. jMusic can read and write MIDI files, audio files, and its own .jm files. jMusic is designed to be extendible, encouraging you to build upon the functionality of jMusic by programming in Java to create your own music composition tools.
Swami is an instrument patch file editor using SoundFont files that allows you to create and distribute instruments from audio samples used for composing music. It uses FluidSynth, a software synthesizer, which has real time effect control, support for modulators, and routable audio via JACK. This project supersedes the Smurf SoundFont Editor, and is an entire object-oriented rewrite of it. The supporting libraries are GUI-independant and can be used in your own programs for doing SoundFont manipulation.
Hydrogen is a simple real-time Drum machine/sequencer. It features a graphical user interface based on Qt, a sample-based audio engine, Jack/ALSA/OSS/PortAudio and Export to disk audio drivers, ALSA MIDI input, ability to import/export XML-based song and drumkit files, 192 ticks per pattern, 16 voices with volume, mute, solo, ADSR, and pan capabilities, and import of samples in wave, au, and aiff format.
Javasynth is a Java-based system for creating (rather experimental) modular audio systems called sound modules. This allows synthesizers of some kind to be assembled in a modular fashion using oscillators, amplifiers, envelopes, filters, and other components familiar to those that have worked with hardware synthesizers. It includes a separated synth engine and a Swing user interface for building sound modules.
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.
The Audio* Music Synthesis Project is music creation software. Currently it features Mojo Synth which is a polyphonic analog modelling synth that has a 64 step sequencer and can also be played from a MIDI keyboard. It attempts to emulate classic analog sounds from Roland M-100, Korg MS-20, and Mini Moog synthesizers.