OpenFisca is free software made available under the AGPL licence. This means that you are free to use, install and modify it with the promise to contribute back your changes to the community. This is the only way a contributive digital common can be made sustainable. All contributions are welcome as long as they abide by our contribution guidelines. We are happy to have you here in the OpenFisca community.
If you provide results based on OpenFisca usage, crediting the project would be very welcome to increase its visibility and contributor base. More people means more maintenance and more upgrades.
The following HTML snippet can be used to credit OpenFisca in your articles and publications:
<a href="https://openfisca.org" target="_blank" rel="noopener">
Computed by <img alt="OpenFisca" src="https://openfisca.org/img/logo-openfisca.svg" height="24" />.
</a>
<a href="https://openfisca.org" target="_blank" rel="noopener">
Calculé par <img alt="OpenFisca" src="https://openfisca.org/img/logo-openfisca.svg" height="24" />.
</a>
If you provide a service that uses OpenFisca, either bundled in a program or serving it over the network, be it directly or wrapped through another API layer, you have to credit OpenFisca, by providing a link to its source code and licence.
The following HTML snippet can be used to credit OpenFisca, for example by placing it in your footer or “about” page. Please make sure to update the destination of the source code link if you use a modified version!
<span>Computations powered by
<a href="https://openfisca.org" target="_blank" rel="noopener"><img alt="OpenFisca" src="https://openfisca.org/img/logo-openfisca.svg" height="24" /></a>,
whose <a href="https://github.com/openfisca/openfisca-core">source code</a>
is used under an <a href="https://choosealicense.com/licenses/agpl-3.0/" target="_blank" rel="noopener">AGPL</a> licence.
</span>
<span>Calculs fournis par
<a href="https://openfisca.org" target="_blank" rel="noopener"><img alt="OpenFisca" src="https://openfisca.org/img/logo-openfisca.svg" height="24" /></a>,
dont le <a href="https://github.com/openfisca/openfisca-core">code source</a>
est utilisé sous licence <a href="https://choosealicense.com/licenses/agpl-3.0/" target="_blank" rel="noopener">AGPL</a>.
</span>
If you modify or extend OpenFisca, you are legally required to make those changes available to the community. The easiest way to do it is to publish your fork of the core package, and any country package, extension or reform, on a source hosting platform such as GitHub, and to notify the core team of this publication.
You can read this analysis to get more insight into what you can and can’t do with APGL-licensed software.
If you see opportunities in developing services/businesses/tools on top of OpenFisca but are concerned with the AGPL3 licence implications, please open an issue to have a public discussion on the topic.