@freeplay I don't really see the point of the EUPL. It's a strong copyleft license (and attempts to close the SaaSS loophole similarly to the AGPL) but at the same time explicitly provides for compatibility with several other licenses, including those with weaker copyleft (like the Eclipse Public License and the GPL), which makes the stronger copyleft provisions pointless.
I would probably use AGPLv3-or-later.