About the Concrete Framework license

Zama’s Concrete framework uses the BSD-3-clear license, which is a common, highly permissive open source license. However, this license does not explicitly cover patents, which is why we added an exemption that gives you the right to use our code (including the patents contained in it) for free for research, evaluation and prototyping purposes, as well as for your personal projects. The exemption does not grant any rights for commercial purposes. Therefore, if you want to use Concrete in a commercial product, you will need to purchase a separate commercial license by emailing us at hello@zama.ai. If you plan on open sourcing software that includes Concrete, we suggest the following:

  • if you include Concrete as a dependency of another open source project, you are free to use any BSD3 compatible license for your project as long as you respect the conditions set out in the license. However, your users will also need to comply with the license when using your code, just like they will need to comply with the license of every other dependency you include. We suggest that you add the following text in your README: “This software uses several dependencies that have different licenses. It is the responsability of the user of this software to ensure they have the proper rights to the underlying dependencies”.

  • if you fork Concrete and make changes to it, you must retain the original BSD-3-clear license with Zama’s exemption. This is to ensure your users don’t end up confused as to what they can do or not. To make things simpler, we encourage you to become an official contributor to Concrete by emailing us as hello@zama.ai so that we can integrate your changes into the main codebase.


Also see this blog post by @rand : How we monetize our open-source products at Zama