The Advanced Linux Sound Architecture is composed of several parts. The first is a fully modularized sound driver which supports module autoloading, devfs, isapnp autoconfiguration, and gives complete access to analog audio, digital audio, control, mixer, synthesizer, DSP, MIDI, and timer components of audio hardware. It also includes a fully-featured kernel-level sequencer, a full compatibility layer for OSS/Free applications, an object-oriented C library which covers and enhances the ALSA kernel driver functionality for applications (client/server, plugins, PCM sharing/multiplexing, PCM metering, etc.), an interactive configuration program for the driver, and some simple utilities for basic management.
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.
Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.
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.
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).
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.
The Psychosynth project aims to create an interactive, modular soft-synth inspired by the ideas of the Reactable. It provides a clean object oriented API to allow the creation of new innovative interfaces for the synthesizer and a 3D simulator of a Reactable-alike device with support for collaborative music creation over the network.
PHP Voice (formerly known as PHP VXML) contain four classes that assist in developing voice application using PHP. It supports Speech Synthesis Markup Language 1.0, Speech Recognition Grammar Specification 1.0, Voice Browser Call Control: CCXML 1.0, and Voice Extensible Markup Language (VoiceXML) 2.0.
Patel is a small, primitive synthesizer project, designed for making "chiptune" style sounds, and targeted especially at old, low-power, or embedded hardware. Currently it is in the form of a simple prototype program, in the course of developing a synthesizer library. Although it is already largely functional, little work has been carried out on making it usable, and various features are still missing or uncertain.