emergence - granular synth plugin by daniel gergely.
freakshow industries - surreal audio effects, highly recommend.
freesound - a non-profit website that provides a collaborative repository of free audio samples.
juce - c++ framework to create your own audio software!
analog obsession - free, high quality plugins of analog hardware created by rıdvan küçük (tunca).
bedroom producers blog - online magazine for producers and sound designers. announces news on deals and free audio software.
meldaproduction's mfreefxbundle - plugin bundle containing of 38 effects
puredata - music programming language with many tutorials online.
samplebrain - a custom sample mashing app designed by aphex twin and dave griffiths.
triple cheese - a freeware synthesizer plugin by u-he that uses comb filters to generate and modify sound.
valhalla supermassive - twenty-one otherworldly delays and reverbs.
vcv rack - open-source modular synth software, available for windows, macos, and linux.
vital - a spectral warping wavetable synthesizer by matt tytel.
convology xt - convolution reverb library
airwindows consolidated - free library of effects.