Cloud Generator: http://clang.mat.ucsb.edu/software.html
(Mac-OS9 classic only) (free) Developed by Curtis Roads and John Alexander. Cloud Generator synthesizes granular sounds in units called "clouds" and also "granulates" stereo sound files.
Pulsar Generator: http://clang.mat.ucsb.edu/software.html
(Mac-OS9 classic only) (free) Developed by Alberto de Campo and Curtis Roads. It generates sound particles called pulsars. (See Roads (2001) Sound Composition with Pulsars for more information)
Emission Control: http://clang.mat.ucsb.edu/software.html
(Mac-PPC only) (free) Written by David Thall in consultation with Curtis Roads. EC is an interactive real-time program, with many novel features, including modulation of synthesis parameters, multiple sound file input, and variable-Q filtering on a grain-by-grain basis.
(CSound) (free) Chaosynth by Eduardo Miranda uses cellular automata (CA) to control the generation of large number of individual sonic events using a GUI in CSound.
(Win) (free) Developed by Rasmus Ekman, it can granulate 8 streams simultaneously.
(Win/Mac and M4L plugins) (Lite version free) Asynchronous sampled/live granular synthesis by apeSoft
(Win/Mac and M4L plugins) (Lite version free) Microsound Prototypes of Granular Synthesis (Glisson, Pulsar, Grainlet, Trainlet) by apeSoft
MacPOD 2: http://thirdmonk.com/MacPOD.html
(Win/Mac) (free) MacPOD/WinPOD by Chris Rolfe and Damián Keller generates a wide range of effects from time compression/expansion to richly varied spectral transformations. MacPOD is named in honour of the original POD GSAMX system developed by Barry Truax at Simon Fraser University.
(Win) (free) Developed by Nicolas Fournel (currently offline - hoping it will be back soon)
AL & ERWIN: https://www.keele.ac.uk/music/people/rajmilfischman/rajmilfischmanfreesoftware/
(Win) (free) Developed by Rajmil Fischman, the AL...gorithmic Compositional Environment in conjunction with ERWIN applies the solutions of Schröedinger’s equation for an atomic potential with radial symmetry (a well-known equation from Quantum Mechanics) to the creation of granular clouds.
(Win/Mac) (free) Developed by Rajmil Fischman, real-time asynchronous granular synthesis of four seperate sound buffers.
jMusic Online Granulator: http://www.granularsynthesis.com/jgrain.php
(Win/Mac/*nix) (free) Developed by Tim Opie using jMusic, it runs online, if you have java enabled....(does anyone now?)
(Win/Mac) (free trial) : Real-time improvisation software with 6 loop players each with granular synthesis and many other effects.
(Mac-PPC only) Real-time granular synthesizer, OSX-PPC updated version of the Real-Time Granular Synthesizer for Mac OS8.
(CSound) (free) Partikkel csound opcode desigedn by Oeyvind Brandtsegg, implemented by Thom Johansen and Torgeir Strand Henriksen, with a vast array of parameters to tweak.
Atomic Cloud: http://atomiccloud.gersic.com/
(Win) (free) The Atomic Cloud Grain Cloud Generator takes an audio file as input, and generates a granular synthesis grain cloud in real time.
Sample Toy: http://www.mrkbrz.com/sampletoy/
Curtis Heavy: http://itunes.apple.com/us/app/curtis-heavy-granular-synthesizer
Narrativas Sonoras II: http://ruipenha.pt/software/narrativas-sonoras-ii/
Grain Science: https://itunes.apple.com/app/id487233637
REplay PLAYer: http://www.essl.at/works/replay.html
(iPad) Multi-streams real-time granular playground able to generate a wide range of usual and not so usual effects by apeSoft
(iPad) Real-time software capable of all time-domain varieties of granular synthesis (Glisson, Pulsar, Grainlet, Trainlet) by apeSoft
Generative 2: https://sirenaudio.co.uk/collections/frontpage/products/generative-2
Music Programming Environments that have Granular Synthesis Capability:
Impromptu: (M) http://impromptu.moso.com.au
Max 5 (Max/MSP): (WM) http://www.cycling74.com/products/maxmsp.html
AudioMulch 2: (WM) http://www.audiomulch.com/
SuperCollider: (WMU) http://supercollider.sourceforge.net/
Composers Desktop Project: (WM) http://www.composersdesktop.com/
Reason: (WM) http://www.propellerheads.se/products/reason/
Logic Pro: (M) http://www.apple.com/logic-pro
SynthEdit: (W) http://www.synthedit.com/
Reaktor 6: (WM) https://www.native-instruments.com/en/products/komplete/synths/reaktor-6/
Kyma X: (WM) http://www.symbolicsound.com/cgi-bin/bin/view/Products/WebHome
Bidule: (M) http://www.plogue.com/products/bidule/
Buzz: (W) http://jeskola.net/buzz/
MachFive 3: (WM) http://www.motu.com/products/software/machfive/technology.html
ixiQuarks: (M) http://ixi-audio.net/content/download/ixiquarks/index.html
Usine: (WM) http://www.sensomusic.org/
Granular Synthesis Plug-ins (mostly VST):
crusherX Studio: http://www.crusher-x.de/
Padshop Pro: http://www.steinberg.net/en/products/vst/padshop/padshop_pro.html
HALion 5: https://www.steinberg.net/en/products/vst/halion_und_halion_sonic/halion_5.html
Granulator II: http://www.monolake.de/technology/granulator.html
(for Max and Max4Live)
The Mangle: http://sound-guru.com/software/mangle/
(for Max and Max4Live)
The Synthesis ToolKit in C++ (STK): https://ccrma.stanford.edu/software/stk/
(C++ Library) (OSS, free) The Synthesis ToolKit in C++ by Perry R. Cook and Gary P. Scavone is a set of open source audio signal processing and algorithmic synthesis classes written in the C++ programming language. STK was designed to facilitate rapid development of music synthesis and audio processing software, with an emphasis on cross-platform functionality, realtime control, ease of use, and educational example code.