Edit: Most of my original comment is wrong, because I failed to note that the EUPL's compatibility clause allows the software to be relicensed under a weaker co

Edit: Most of my original comment is wrong, because I failed to note that the EUPL's compatibility clause allows the software to be relicensed under a weaker copyleft license (Eclipse Public License v1). The FSF explains: https://www.gnu.org/licenses/license-list.en.html#EUPL-1.2 https://www.gnu.org/licenses/license-list.en.html#EUPL-1.2 EUPL v1.2 was published in 2017. It's not a new license. --- > or otherwise making available, online or offline, copies of the Work or providing access to its essential functionalities This part suggests that the EUPL is even stronger than AGPLv3 (Edit: incorrect, see https://www.gnu.org/licenses/license-list.en.html#EUPL-1.2 https://www.gnu.org/licenses/license-list.en.html#EUPL-1.2 ), since the "communication" doesn't have to take place over a network. Neither GPLv3 nor AGPLv3 requires the corresponding source code to be made available to a user who interacts with preinstalled (A)GPLv3-licensed software on someone else's hardware (such as a voting machine).* The EUPL would require (Edit: incorrect) the source code to be provided in this case, since the hardware is providing the user with access to the software's "essential functionalities". The EUPL explicitly lists AGPLv3, GPLv2, GPLv3, and other popular copyleft licenses as "Compatible Licences" to clarify that EUPL-licensed software can be combined with other copyleft-licensed software. * https://www.gnu.org/licenses/gpl-faq.html#v3VotingMachine https://www.gnu.org/licenses/gpl-faq.html#v3VotingMachine