JUCE is an open-source cross-platform C++ application framework for desktop and mobile applications, including VST, VST3, AU, AUv3, RTAS and AAX audio plug-ins.

Synthesizer plug-in (previously released as Vember Audio Surge)

Enhanced version of Cockos' iPlug - A simple-to-use C++ framework for developing cross platform audio plugins and targeting multiple plugin APIs with the same code. VST / VST3 / Audiounit / RTAS / AAX (Native) formats supported. NOTE: THIS IS OBSOLETE, PLEASE SEE IPLUG2:

A curated list of my favourite music DSP and audio programming resources

VST 3 Plug-In SDK

C++ Audio Plug-in Framework for desktop, mobile and web [PRE-RELEASE]

An audio plugin with Pure Data embedded that allows to load and to control patches

A user interface toolkit mainly for audio plug-ins

DSP servers using general purpose networks and computers - https://audiogridder.com

Audio plugin framework. VST2/VST3/AU/AAX/LV2 for Linux/macOS/Windows.

A modern and transparent way to use Windows VST2 and VST3 plugins on Linux

native node addon that allows for instantiation of natively installed VST3 audio plugins

SFZ parser and synth c++ library, providing AU / LV2 / VST3 plugins and JACK standalone client

Various resources related to developing plugins for audio production.

A lightweight VST2/3 framework

Graph-based audio api for Node.js based on LabSound and JUCE

Collection of JUCE synthesisers utilising the Maximilian library.

A basic and experimental guitar modeling amp

VST delay plugin where the repeats degrade in resolution

A VST reverb effect in which the reflections can be frozen, filtered, pitch shifted and ultimately disintegrated.

Collection of tutorials & resources for the C++ library JUCE

VST plugin version of the WebSID Commodore 64 synthesizer

A VST / VST3 / AU / LV2 Reverb Plugin

VST3 version of system-supplied Mac OS X AUNetSend audio plugin.

My curated list of audio DSP and plugin development resources

Audio plugin that lets you use MIDI to pitch-shift via delay to turn unpitched audio into melodies

EP-MK1 is a real-time physical model plugin of an Electric Piano built with Pure Data and Camomile.

Example of a self contained VST3/VST2 plugin that is not part of the SDK

Vst3HostDemo

AAX / AU / VST / VST3 FM synthesizer which emulates the Yamaha OPL sound chip used in PC sound cards from the 90s.