Yes, "Euro-Office" was launched this week. It is a European fork of "OPENOFFICE".

It is open source and supported by Nextcloud, IONOS, Proton, Tuta and more.[1]

I haven't tried it out, bu you can find the documentation on how to host it yourself here: https://euro-office.github.io/documentation/

A more mature alternative would is Nextcloud as it offers a lot more, but setup is reportedly more involved. It does appear to be available for enterprise customers as hosted version as well though: https://nextcloud.com/office/

[1] https://github.com/Euro-Office