VCV Rack is free/open-source software, but you should still familiarize yourself with the VCV Rack licenses before releasing your plugin, to avoid misuse of intellectual property. If in doubt, send your licensing questions to firstname.lastname@example.org.
Since Rack is licensed under GPLv3, you may license your plugin under GPLv3 as well.
VCV recommends that supporters of free/open-source software license their Rack plugins under GPLv3+ (SPDX license identifier
This license gives users the Four Essential Freedoms of free software and follows OSI's Open Source Definition.
Licensing your Rack plugin under GPLv3+ requires that derivative works are also licensed as free software under the GPLv3. This prevents a company from turning your source code into proprietary (non-free) software without your explicit permission.
Rack offers a VCV Rack Non-Commercial Plugin License Exception which allows you to license your plugin under any terms of your choice, as long as it is offered free of charge. You may choose:
Note that if you copy significant portions of Rack's code into your own plugin, you must license it under GPLv3.
If someone makes a fork of your non-GPLv3 open-source plugin that is not a Rack plugin (e.g. a port to VST or a digital hardware module), their source code becomes no longer linked to VCV Rack and is thus no longer a “derived work” of Rack, so Rack's license does not apply to their source code.
VCV offers commercial royalty licensing for Rack plugins by emailing email@example.com. This license also includes permission to use the Component Library graphics by Grayscale, which are normally licensed for non-commercial use only.
It is recommended to contact VCV as early as possible in your development process to make sure the license agreement is ready well before you release your plugin. You can expedite the licensing processing by sending concepts or design mockups along with your license request.
You may also wish to sell your plugin on the VCV Library. Some benefits of distributing your plugin on the VCV Library:
It is recommended to follow these guidelines for all plugins, but you are not legally obligated to do so. However, it is a requirement for: