OnlyOffice invokes AGPLv3, says Nextcloud must restore removed logos in Euro-Office fork

Last month, Nextcloud and a bunch of other European tech firms came together and created a new project, called "Euro-Office," forked from OnlyOffice, with the aim to serve as a "sovereign replacement" to the behemoth that is Microsoft Office.

But shortly after the project took off, OnlyOffice came along, basically claiming that Euro-Office's decision to strip its branding and logos violated the GNU Affero General Public License v3 (AGPLv3). The company then killed its 8-year-old partnership with Nextcloud. That partnership allowed Nextcloud users to edit office documents using OnlyOffice's engine directly within the Nextcloud interface.

A few days ago, on the 17th, Nextcloud responded to OnlyOffice's accusations by publishing a deep legal analysis defending the fork. Nextcloud asserted OnlyOffice's strict logo retention demands harm the spirit of open source software by restricting fundamental user freedoms (to run, study, modify, and distribute the code), and engineers engineered a clever legal workaround to OnlyOffice's proprietary traps using an interpretation backed by Bradley M. Kühn, the original author of AGPL.

The license's Section 7 allows authors to add specific terms like warranty disclaimers (7a), preservation of legal notices (7b), and prohibiting misrepresentation of origin (7c). OnlyOffice had claimed its logo retention was just an "author attribution" allowed under Section 7(b), but Nextcloud argued that a corporate logo is a trademark, not simple attribution. Because the logo rule was a "further restriction", it invoked the AGPLv3's "self-cleaning" mechanism:

If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term

The Free Software Foundation (FSF) backed this interpretation in a January blog post, clarifying that attribution applies to natural persons, not corporate branding.

Now, OnlyOffice has published its own "nuh-uh" rebuttal to Nextcloud, claiming that the FSF's 2026 blog post is just an opinion. OnlyOffice's open letter states that the actual 2007 text of the AGPLv3 is the only binding legal source, and the FSF's recent commentary is just a "later interpretation" that does not legally amend the original license.

Regarding the idea that logos are trademarks, not attribution, OnlyOffice's letter points out that the 2007 license text never actually defines the term "author attributions." The company argues its licensing approach was established long before the FSF suddenly decided to narrow the definition this year.

Instead of continuing the fight over branding, OnlyOffice has proposed what it calls a "constructive" path forward. The letter demands that Euro-Office change its UI and source code.

OnlyOffice insists that Section 5(d) of the license means that even without specific logos, Euro-Office must have an accessible "About" page clearly identifying ONLYOFFICE as the original developer and stating the software is modified. It also demands that Euro-Office retain notices in the source code identifying the project's origins and that public materials, like the repository description, must be corrected to show Euro-Office is a derivative work.