OPEN_SOURCE_PLUGINS_AND_SOFTWARE.md

Open Source Plugins & Software

A list of open source audio software that you can inspect and learn from, along with the language and framework used to make them.

Open Source Plugins

Collections

(Note, I'm avoiding listing individual plugins in the Synths/Audio FX/MIDI FX/Meters & Visualizers sections if they appear in one of these collections. A few exceptions are made for plugins that are particuarly notable.)

• Airwindows Plugins | (C++, gui-less, raw plugin APIs) | - Lots of good quality effects and experiments developed over many years.
  • There are a ton of plugins here, so here is a list of some community favorites:
    • density
    • ironoxide
    • pressure4
    • totape5
  • airwin2rack | (C++, JUCE, VCV Rack) | - All of the Airwindows plugins consolidated into a single plugin with GUI. Can also be used as a static libray for inclusion into other projects.
• ardura's plugins | (Rust, nih-plug, egui) | - A collection of neat synths and effects with nice-looking GUIs. Written in Rust, nih-plug, and egui.
• brummer10's plugins | (C++, libxputty, raw plugin APIs, JUCE) | - A large collection of mostly guitar-focused effects. guitarix is one of the more popular ones.
• Calf Studio gear | (C++, custom GTK framework) | - A large collection of plugins aimed at a professional audience.
• Chowdhury DSP | (C++, JUCE) | - A collection of high quality effect plugins (as well as a kick drum synthesizer). A lot of these plugins make use of use of cutting-edge neural network inferencing.
• Cool Panda Plugins | (C++, JUCE) | - A collection of creative effects.
• Destroy FX | (C++, custom GUI framework based on VSTGUI, raw plugin APIs) | - A collection of effects that "destroy your sound".
• DISTRHO Dear Plugins | (C++, DPF, Dear ImGui) | - A collection of plugins demonstrating how to use the Dear ImGui library with the DPF framework. Still a work in progress.
• DISTRHO Plugin Framework | (C++, DPF) | - Has a list of plugins that were made using this framework.
• DISTRHO-Ports | (C++, JUCE) | - A whole bunch of plugins ported to work on Linux/LV2.
• Dplug | (D, Dplug) | - Contains some example plugins using the framework.
• EQ10Q | (C++, custom GTK framework) | - A suite of plugins containing a 10-band parametric equalizer, gate, compressor, bass enhancer, and mid-side encoders.
• GuitarML | (C++, JUCE) | - A collection of electric guitar effects that use neural network models to emulate real-world hardware.
• JoepVanlier's JSFX plugins | (JSFX, Lua) | - A collection of cool plugins and scripts for Reaper. Some of the GUIs are really stunning.
• lkjb plugins | (C++, JUCE) | - Additional plugins made by the creator of Luftikus.
• LSP Plugins | (C++, custom GUI framework) | - A collection of good quality mixing/mastering effects for Linux.
• Maeror's VST3 plugins | (Rust, nih-plug, Vizia) | - A collection of simple effects written in Rust, nih-plug, and Vizia.
• Mrugalla Plugins | (C++, JUCE) | - A collection of modern and unique plugins by Florian Mrugalla.
• Mutable Instruments' Eurorack Modules | (C++, custom embedded framework) | - The source code for a large collection of popular, high quality Eurorack modules.
• nih-plug | (Rust, nih-plug, egui, Iced, Vizia) | - Contains a collection of plugins written in Rust, including the amazing Spectral Compressor plugin.
• Shiru Plugins | (C++, DPF) | - A suite of old video-game sound chips synths and effects.
• sjaehn | (C++, Pugl) | - Several cool MIDI based slicing/glitching effects and synthesizers.
• SocaLabs Plugins | (C++, JUCE) | - A collection of plugins made by SocaLabs.
• SOUL-VA | (SOUL) | - A non-trivial virtual analog filter library written in SOUL. Plugin versions are also sold as commercial products.
• VCV Library database - An official database of VCV Rack plugins, containing both commercial and open source plugins.
• x42-plugins | (C, robtk, Pugl) | - A collection of good quality effects and visualizers. Some plugins are also sold as a commercial product.
• zam-plugins | (C++, DPF) | - A suite of good quality mixing/mastering plugins.
• ZL-Audio Plugins | (C++, JUCE) | - A collection of good quality plugins including a fancy parametric equalizer, saturator, and compressor.

Synths

• ADLplug | (C++, JUCE) | - Emulation of FM-synthesizers found in some classic game consoles.
• Bespoke Synth | (C++, JUCE) | - A very modular synthesizer with support for complex routing, modulation, and sequencing. It can even host VST plugins, blurring the lines between synth and DAW.
• Cardinal | (C++, DPF) | - An open source modular synthesizer plugin that can host VCV Rack plugins.
• Dexed | (C++, JUCE) | - Synthesizer closely modelled after the Yamaha DX7.
• DigiDrie | (Faust, C++, DPF) | - A "monster" monophonic synth.
• Fabla 2 | (C++, custom GUI framework) | - A multi-sampler plugin with a drum pad layout.
• Firefly Synth | (C++, JUCE) | - A feature-rich semi-modular software synthesizer and fx plugin.
  • It is the bigger brother to the discontinued InfernalSynth plugin.
• Geonkick | (C++, C, custom GUI framework) | - Advanced drum synthesizer.
• gRainbow | (C++, JUCE) | - A synthesizer that uses pitch detection to choose candidates for granular synthesis or sampling.
• Helm | (C++, JUCE) | - High-quality modern monophonic synthesizer. The older sibling to Vital. The oscillators are not stereo though.
• jc303 | (C++, JUCE) | - A nice Roland TB-303 clone.
• Mika Micro | (C++, WDL-OL) | - A nice and simple synthesizer with a clean design.
• Monique Mono-Synth | (C++, JUCE) | - High-quality subtractive monophonic synth. Now open source!
• Ninjas 2 | (C++, DPF) | - Sample slicer and player.
• OB-Xd | (C++, JUCE) | - A high quality subtractive analog synth modeled after the Oberheim OB-X.
• OctaSine | (Rust, Iced, raw plugins APIs) | - A versatile FM synth written in full-stack Rust.
• Odin 2 | (C++, JUCE) | - Modern analogue-modeled hybrid synthesizer.
• OS-251 | (C++, JUCE) | - A nice sounding lo-fi synthesizer.
• sfizz | (C++, Faust, VSTGUI) | - A sampler that plays SFZ files. (SFZ is like SoundFonts but with more features).
• Spiro | (C++, JUCE) | - A semi-modular synthesizer with a beautiful interface.
• Surge XT | (C++, JUCE) | - Feature-rich hybrid synthesizer that was once sold as a proprietary product. (It has since evolved into its own thing with many new features added.)
• Synth2 | (D, Dplug) | - A recreation of the classic Synth1 virtual synth. (Still a work in progress).
• Tunefish | (C++, JUCE) | - A neat little additive synthesizer.
• Vaporizer2 | (C++, JUCE) | - Feature-rich wavetable synthesizer that was once a proprietary product.
• Vital | (C++, JUCE) | - An incredibly powerful and high quality modern synthesizer. Rivals the likes of Xfer Serum and NI Massive.
  • There is also a fully GPLv3-licensed fork called Vitalium that has all the non-GPL stuff removed.
• Wavetable | (C++, JUCE) | - Sleek wavetable synthesizer with a great clean sound.
• ZynAddSubFX | (C++, DPF) | - Feature-rich additive synthesizer with a great clean sound. Also sold as a commercial product.

Audio FX

• Aether | (C++, Pugl) | - Beautiful shimmering reverb based on the CloudSeed plugin by Valdemar Erlingsson. I choose this over the original as that uses a Windows-only C# platform for its GUI.
• AIDA-X | (C++, DPF) | - An amp model player that can load AI-trained models of music gear.
• BinAural | (C++, JUCE) | - A mono-to-stereo plugin that positions sound in a 3D space using Head-Related Transfer Functions.
• CloudReverb | (C++, DPF) | - Another reverb plugin based on the CloudSeed plugin by Valdemar Erlingsson. I choose this over the original as that uses a Windows-only C# platform for its GUI.
• Cocoa Delay | (C++, WDL-OL) | - A nice delay plugin with ducking, saturation, filtering, and pitching features.
• CTAG Dynamic Range Compressor | (C++, JUCE) | - A simple general-purpose compressor plugin.
• DelayArchitect | (C++, JUCE) | - A feature-rich delay designer plugin.
• Dragonfly Reverb | (C++, DPF) | - Algorithmic reverb based on Freeverb.
• Fire | (C++, JUCE) | - A multiband waveshaper with a great looking UI.
• Flutterbird | (C++, WDL-OL) | - Simple multi-lfo than modulates pitch and volume, creating a "fluttering" effect.
• Free Clip | (C++, JUCE) | - A nice sounding waveshaper plugin.
• Frequalizer | (C++, JUCE) | - An equalizer plugin using JUCE's new dsp module.
• Fogpad | (C++, DPF) | - Reverb plugin where reflections can be frozen, filtered, pitch-shifted, and mangled.
• lamb | (Faust, Rust, nih-plug, Vizia) | - A clean lookahead compressor/limiter.
• Luftikus | (C++, JUCE) | - Analogue modeled equalizer.
• MAIM | (C++, JUCE) | - A unique distortion effect which "circuit bends an MP3 encoder in real time".
• Misstortion | (C++, JUCE) | - Good quality hard/soft clipper.
• Molot Lite | (C++, iPlug2) | - A cut-down version of the Molot compressor by Tokyo Dawn Records. It has a lot of color and character.
• Mverb | (C++, DPF) | - Nice-sounding plate reverb.
• PeakEater | (C++, JUCE) | - A nice waveshaping plugin with a sleek UI.
• Reach | (C++, Faust, JUCE) | - Extraterrestrial reverb with a unique sound. It is also sold as a commercial product.
• Room Reverb | (C++, JUCE) | - Nice sounding algorithmic reverb based on Freeverb.
• Squeezer | (C++, JUCE) | - Flexible general-purpose audio compressor with a "touch of citrus".
• TimeStretch | (Rust, SuperCollider, Python, gui-less) | - A refinement of the famous PaulStretch time stretching effect. Includes a PDF explaining the DSP.
• Valentine | (C++, JUCE) | - A nice compressor/saturator that is meant to "pump and breath".
• VitaliumVerb | Rust, nih-plug, gui-less | - A Rust port of the reverb module from the Vital/Vitalium synthesizer, with some added improvements and optimizations.
• Wolf Shaper | (C++, DPF) | - Good quality waveshaper with support for unlimited nodes.

MIDI FX

• Helio Workstation | (C++, JUCE) | - A very modern and feature-rich sequencer.
• QMidiArp | (C++, robtk, Pugl) | - Advanced arpeggiator, sequencer, and MIDI LFO.
• Ripchord | (C++, JUCE) | - A MIDI plugin that can create, perform and remix chord progressions.
  • There is also a fork that adds support for Linux.
• ShowMIDI | (C++, JUCE) | - A tool to effortlessly visualize MIDI activity.
• Stochas | (C++, JUCE) | - An advanced probabilistic polyrythmic sequencer. Made by the same team behind the [Surge XT] synthesizer.

Meters & Visualizers

• EasySSP | (C++, JUCE) | - Real-time spectrum analyzer and stereo analyzer plugin.
• K-Meter | (C++, JUCE) | - A feature-rich loudness meter.
• LUFS Meter | (C++, JUCE) | - Real-time loudness meter with support for several international loudness standards.
• MultiMeter | (C++, JUCE) | - A swiss-army-knife metering plugin with a sleek UI.
• Spectacle | (C++, DPF) | - Modern real-time spectrum analyzer plugin.
• Wolf Spectrum | (C++, DPF) | - Real-time heat-map spectrum analyzer plugin.

Open Source Software

DAWs & Hosts

• Ardour - Feature-rich DAW. Focuses more on recorded music production over electronic music production.
• Audacity - Popular multi-track audio editor. There is also a fully-libre open source fork called Tenacity.
• Bass Studio - A feature-rich DAW that was recently made open source.
• Bespoke Synth - A very modular synthesizer with support for complex routing, modulation, and sequencing. It can even host VST plugins, blurring the lines between synth and DAW.
• Cardinal - An open source modular synthesizer plugin that can host VCV Rack plugins.
• Carla - Cross platform plugin host with support for many plugin formats.
• Hydrogen - An advanced drum sequencer for Linux, MacOS, and Windows.
• LMMS - Feature-rich DAW focused on electronic music production. Contains many built-in synths and effects.
• Mixxx - Popular cross-platform application for performing live DJ mixes.
• pxtone collab - A music editor with collaborative editing features.
• Stargate - A new and lightweight DAW with a powerful routing matrix and a suite of built-in plugins. It also aims to run well on low-spec hardware such as Raspberry Pi's.

Musical Notation

• composing.studio - An experimental open-source web app that allows you to collaborate on editing sheet music.
• MuseScore - A popular and mature open-source sheet music editor.

Other

• Sæmpl - A sample manager that can automatically sort samples by properties like loudness, pitch, and tempo.
• Ultimate Vocal Remover - A state-of-the-art program that uses machine learning to separate vocals from a mix.

More Lists

• Awesome Linux Clap List - A list of FOSS clap plugins that work for Linux
• OpenAudio - A large list of open source audio plugins, apps, and other projects.
• SpotlightKid's list - A large, actively updated list of open source audio plugins and apps.
• StudioRack - An app for browsing and downloading from a large catalogue of open source plugins and multisample instruments.