How to Find Open-Source Audio Plugins on OpenAudio

Updated

OpenAudio (openaudio.webprofusion.com) is a curated catalog of open-source audio software, organized into four main sections: Audio Plugins, Collections, Audio Apps, and Software Development Libraries & APIs. To find a plugin, open the site and browse the Audio Plugins table, which lists each project with a description, a type (Instrument, Effect, or Misc), and the framework it was built with (most commonly JUCE). From there, follow the linked project page or GitHub repository for downloads and source code. This guide suits anyone who wants a free, open-source plugin for music production or a reference implementation for audio development.

What the OpenAudio catalog contains

The site's stated intent is to catalog open-source audio apps, plugins (VSTs and similar formats), and other resources that are either fully featured or serve as useful examples with non-trivial features. The page is divided into these sections:

  • Audio Plugins — the largest section, presented as a table of individual plugins.
  • Collections — grouped sets of projects.
  • Audio Apps — standalone applications.
  • Software Development Libraries & APIs — code libraries for building your own audio software.
  • Code Samples and Open Data Resources — additional reference material.

How the plugin table is structured

Each row in the Audio Plugins table gives you three pieces of information you can use to filter quickly:

Column What it tells you Example from the page
Description What the plugin does "ÆLAPSE is a delay and reverb plugin. The delay is based on tape-delay mechanisms, while the reverb is inspired by (but not limited to) spring reverbs."
Type Instrument, Effect, or Misc ÆLAPSE is listed as an Effect
Framework The toolkit it was built with JUCE

The Type column is the fastest way to narrow down. If you need a synthesizer, scan for Instrument entries such as ADLplug (an FM chip synthesizer for OPL & OPN), amsynth (analog-modelling), or Audible Planets (a semi-modular synthesizer). If you need processing, scan for Effect entries such as Ambience (an algorithmic reverb built on a 16-channel Feedback Delay Network), Argotlunar (a real-time delay-line granulator), or ANATOMY (transient/tonal separation with independent multi-effect chains per component).

Step-by-step: finding a plugin that fits your setup

  1. Open the site at openaudio.webprofusion.com and go to the Audio Plugins section.
  2. Filter by Type — decide whether you need an Instrument, an Effect, or something in Misc (for example, ampli-Fe is listed as Misc and is a cross-platform VST2 plugin written in Rust).
  3. Check the Framework column if you care about compatibility or plan to modify the code. JUCE dominates the list, but not exclusively — amsynth uses GTK, and Airwindows is listed with no framework.
  4. Read the description to confirm the plugin does what you need. Descriptions are specific: 3HSPlug is a GM/GS-compatible multi-timbral 8-operator FM/PCM synthesizer, while AnalogChannel is a VST3 channel strip aimed at mixing engineers who want fast, characterful results.
  5. Follow the project link to reach the source repository, where you'll find builds, documentation, and license terms. The site itself is a directory — it does not host downloads.

Contributing a project

If you maintain an open-source audio project and want it listed, the site directs you to fill out its issue template on GitHub (github.com/webprofusion/OpenAudio/issues). The change is prepared automatically and reviewed by an editor before it appears.

Common sticking points

  • The catalog is a directory, not a store. There is no download button on OpenAudio itself; every plugin links out to its own project page or repository.
  • Format varies by project. The table's Type column describes function, not plugin format. A project may ship as VST2, VST3, AU, CLAP, or a standalone executable — Aeolus, for instance, is offered as VST, AU, CLAP, or standalone. Confirm the format on the project's own page.
  • Framework is a build detail, not a compatibility guarantee. Knowing a plugin uses JUCE tells you about its codebase, not which operating systems or DAWs it supports.
  • No pricing information is listed. The catalog describes projects as open source, but license terms live with each individual project — check them at the source before using a plugin commercially.