Sonicbirth
SonicBirth is an AudioUnit designing application. The first in its category, it allows users to build their own AudioUnit plugins, either by working with existing circuits or by creating circuits completely from scratch. SonicBirth is also an AudioUnits package, as it comes bundled with a set of plugins designed for standalone use as plugins as well as pre-constructed circuits to modify or build upon for creating new plugins

Bidule
The brainchild of Plogue Art et Technologie, Bidule is a cross-platform application that is gaining recognition world-wide as the new standard in modular music software

Granulab
PC free ware.
GranuLab is a real-time granular sythesizer. It uses a built-in sine wave or you may load a sound file as raw material for sound production.
Granular synthesis provides independent control over time-stretching and the pitch of a sound. You can move freely from straight playback of speech or music to a variety of effects, and back. Some of the effects should be appealing to those who like playing around with analog synthesizers.

KTGranulator
PC and OSX freeware
KTGranulator is a free delay line granulator available as a VST effect plugin with custom editor and as a MacOSX Audio Unit. It was made as an exploration in building VST effect plugins and using the VSTGUI library and was inspired by the great DLGranulator effect in Ross Bencina's AudioMulch.

RTGS
RTGS-X is the new OSX incarnation of the now legendary Real-Time Granular Synthesizer application which was originally released nearly 5 years ago for MacOS 8.6

Thonk
thOnk_0+2 provides the sonic treasure-chest composers can turn to to harvest fresh, unanticipated material to solve their writers blocks with, without having to think at all.
It is an extremely simple to use Freeware Macintosh application, that uses Granular Synthesis to produce very diverse sounds based upon a sound file provided by the user, where you have NO CONTROL WHATSOEVER over the process. Only available for OS9

osxAudio
This site was created to provide the recording/music industry with an invaluable resource as we all make the move to Mac OS X.

Sonasphere
A kinetically driven interactive music enviroment

Computer music programs . Macintosh
Tom Erbe, CalArts School of Music, list of programs with ftp sites made for his sound design class

LEMu is a software application written in JAVA using jMusic and MidiShare. Designed and implemented by electronic musicians, it aims to assist in both the production and performance of electronic music

http://girl.yowstar.com/
Girl is based on a simple idea. Using a library of sound files in the "Sounds" folder, you can select any sound from any folder in the "Sounds" folder, and load it into a GirlModule, which will continuously loop the sound. Within a module you can modify the sound file using the effects and by looping smaller parts of the sound file. You can open any number of these modules, limited only by the amount of RAM and the power of your computer's processor. The modules can be treated individually, or the playback speeds of the loops can all be synchronized to a tempo.

http://www.audiomulch.com/
AudioMulch is software for real-time sound synthesis, music composition and audio processing.

http://sourceforge.net/softwaremap/trove_list.php?form_cat=113%20
Open source software development community

http://geneticmusic.com/
Algorithmic Arts makes software emulations of modular analog sequencers and software for creating algorithmic MIDI music and graphics from Fractals, DNA, EEGs, EKGs, and other dat

http://www.earshot.info/
Free software program Earshot allows the user to trawl the internet & randomly collect sound files, which can be manipulated and re-worked.

http://www.steim.org/steim/
Center for Research & Development of instruments & tools for performers in the electronic performance arts

http://www.ableton.com/
Ableton Live is the music-production solution that allows you to spontaneously compose, record, remix, improvise and edit your musical ideas. Live brings your acoustic, electronic and virtual instruments, as well as your digital audio recordings, together in a single interface with unparalleled ease of use. In the end, Live lets you focus on what really matters: your music.

http://www.cycling74.com/index.html
Max/MSP , Jitter

http://www.waikato.ac.nz/humanities/music/imp.shtml
Good list of software here

http://www.csounds.com/whatis/index.html
Csound is a programming language designed and optimized for sound rendering and signal processing

http://puredata.org/
PD (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical processing. It is the third major branch of the family of patcher programming languages known as Max (Max/FTS, ISPW Max, Max/MSP, jMax, etc.) originally developed by Miller Puckette and company at IRCAM. The core of Pd is written and maintained by Miller Puckette and includes the work of many developers, making the whole package very much a community effort.