sOURnd Docs Your engines
On this page
  1. Free engines
  2. Free closed engines
  3. Paid engines, bought one at a time
  4. Every paid engine, by subscription
  5. Selling what you build
  6. Games
  7. What every paid licence allows and forbids
  8. Your build register
  9. If you build with JUCE
  10. The small print that matters

Licensing

Free engines cost nothing to use, in anything you sell. Paid engines are yours to build into your own plugins and games, bought one at a time or all together with a subscription.

Free Apache-2.0 engine

  1. Downloadno account or email
  2. Any plugin or gamecommercial or GPLv3
  3. Sell itno royalty

Free closed engine

  1. Downloadno account or email
  2. Your own plugins and gamesnot GPL or AGPL
  3. Sell itno royalty

Bought engine

  1. Yours for goodwith updates
  2. As many of your plugins and games as you like
  3. Sell itno royalty

On a plan

  1. Every paid enginewhile the plan is active
  2. What you release while it is activestays licensed for good
  3. Sell itno royalty

Free engines

14 effect engines, the JUCE module and the C header are Apache-2.0. Use them in commercial plugins and in GPLv3 ones, modify them, ship them. Keep the licence notice. (Apache-2.0 is not compatible with GPLv2-only projects.)

Free closed engines

18 more engines are free closed libraries: you download them with no account or email, from any free engine's page. You may use them in your own plugins and products under the same terms as a paid engine below.

  • You own the engine for good, with updates. Updates keep loading settings saved by older versions.
  • Build it into as many of your own plugins as you like, commercial or free, and sell them.
  • New engines are separate purchases.

Every paid engine, by subscription

  • Every paid sournd engine while your subscription is active, including new ones as we release them.
  • If you cancel: plugin versions you released while subscribed stay licensed, for good. New releases, updates of those plugins and new downloads need an active subscription.
  • Access runs to the end of the period you paid for.
  • The subscription covers engines made by sournd. Engines by other authors, when they arrive, are sold separately.

Selling what you build

You can sell what you build, and what it earns is yours. There is no royalty, no revenue report and nothing to register.

This is the licence for engines made by sournd. Engines from other companies, when they arrive, are sold and licensed separately by their makers, and their terms are their own.

  • An engine you bought can go into as many of your own plugins and games as you like, commercial or free, for good.
  • On a plan, every plugin or game version you release while the plan is active stays licensed for good. New releases, updates of those releases and new downloads need an active plan.
  • Apache-2.0 engines are yours to use under that licence.

Games

Engines reach games through the C ABI: the same closed library, linked into your game or into an audio middleware plugin. Today you link the C library yourself; adapters for FMOD, Wwise, Unity and Unreal are on the way.

  • The same licence as for plugins. An engine you own, or a plan that is active when you release, covers your game. There is no per-game fee and no royalty.
  • The library is built for macOS, Linux and Windows today; other platforms follow as their builds are ready.
  • Your players need nothing from sournd: engines run inside your game with no account, licence check or internet connection.

More for game developers: sOURnd for games.

What every paid licence allows and forbids

  • Allowed: compiling the engine into your plugins or games and distributing those to your users or players.
  • Not allowed: passing on the library, header bundle or engine source to anyone else, or offering the engines as a library or service of your own. Each download carries a marker that identifies the buyer.
  • Not allowed: using the engines to build, train, test or supply data to a tool that generates music, audio or performances, or shipping them inside one. A licence used this way ends. An AI assistant that helps you build your own plugin or game is fine. See the terms and how we make things.
  • Your users need nothing from sournd: engines run inside your plugin or game with no account, licence check or internet connection.

Your build register

Your engines page keeps a build register: a record of the plugins, games and apps you or your AI built with your engines, with versions, formats and the download they came from. Adding to it is voluntary and nothing is owed. It is your own history of what your licence covers. AI agents that use sOURnd are asked to offer to record each build, and to keep your library and keys private: the licence is yours, not theirs.

If you build with JUCE

JUCE is a separate product with its own licence and its own plans. A sournd licence does not cover JUCE, and does not change what JUCE asks of you. If your plugin uses JUCE, follow the JUCE 8 licence and choose the JUCE plan that fits what you ship.

The small print that matters

  • GPL plugins: the closed engines (every paid engine and the free closed ones) cannot be linked into a plugin released under the GPL or AGPL, because we do not publish their source. Use the Apache-2.0 engines there.
  • Platforms: downloads are built for macOS (universal), Linux (x86_64 and aarch64) and Windows (x64, MSVC).
  • Apache-2.0 on the bridge does not grant rights to paid engines or to the sournd name and logo.
  • Engines are effects on audio the user supplies or instruments the user plays. They never generate music.
  • An appeal to everyone who uses sOURnd, whatever the licence: please do not use it to build tools that generate music. Why we ask.
  • sournd is a Box Of Rules project. Payments are taken by Box Of Rules through PayPal.
  • Draft terms: these become final before sale.