Beast is a powerful music composition and modular synthesis application. It offers multiple input methods like multitrack, piano roll, and pattern editing and supports skins. On the technical side, it has a wide range of abilities like sequencing, unlimited undo/redo history, real-time synthesis with multiprocessor support, full duplex 32-bit audio rendering, precise timing down to sample granularity, on demand loading of partial wave files, on the fly decoding of various sample formats, aliasing free oscillators, and full Scheme scripting support.
din is a software musical instrument and audio synthesizer. Bezier curves are used to draw and sculpt waveforms, create gating and modulation (FM and AM) patterns, and create delay feedback and volume patterns. You can also create an unlimited number of drones and sculpt their waveforms. It uses JACK to output audio, and supports MIDI, OSC and IRC bot for input. din can be extended and customized with Tcl scripts.
FluidSynth is a real-time software synthesizer based on the SoundFont 2 specifications. It can read MIDI events from MIDI input devices or files and render them to an audio device using SoundFont instrument banks. It can also play MIDI files. Other features include real time effect control and a powerful API for embedding FluidSynth in other programs.
Faust AUdio STreams is an expressive functional programming language for realtime audio signal processing. The Faust compiler translates DSP specifications into efficient C++ code. A variety of platforms and plugin formats are supported. A single Faust specification can be used to easily generate JACK and ALSA applications, as well as LADSPA, MAX/MSP, PD, Q, SC, and VST plugins. In addition to C++ code, the Faust compiler can also generate SVG block-diagram representations as well as XML descriptions.
aubio is a library for audio labelling. Features include onset detection, silence detection, beat tracking, and pitch detection. The goal of this project is to provide automatic labelling features to other audio software projects. Functions can be used offline in sound editors and software samplers, or online in audio effects and virtual instruments.