On March 27 in Berlin, Nextcloud, IONOS and roughly a dozen other European organizations, including Proton, XWiki and OpenProject, announced Euro-Office: an open source component for collaborative editing of documents, spreadsheets and presentations, designed to integrate into platforms like Nextcloud Hub, Proton Docs or OpenProject. It’s not a standalone desktop suite, but a web-based editor embedded within existing work environments. Code is already available in preview on GitHub, with the first stable release expected in summer.

The technical foundation is ONLYOFFICE, and Euro-Office is a direct fork. The consortium chose this path rather than collaborating with the original project for reasons documented in the repository: pull requests systematically ignored, outdated build instructions, code with obfuscated sections or binaries without source, commit messages pointing to inaccessible internal trackers. These are concrete technical grievances, not just philosophical ones.

ONLYOFFICE Strikes Back

Three days later, ONLYOFFICE issued a formal statement accusing Euro-Office of violating the AGPLv3 license. The core issue lies in additional conditions that Ascensio System, the company behind ONLYOFFICE, added to its version of the license in May 2021. Section 7 of AGPLv3 permits copyright holders to impose supplementary requirements, and ONLYOFFICE inserted two: an obligation to preserve the original logo in derivative works and a prohibition on using registered trademarks.

Euro-Office removed both clauses, arguing they contradict each other and are unenforceable anyway because trademark restrictions don’t qualify as valid license conditions. According to Nextcloud, this interpretation is shared by the Free Software Foundation and Bradley M. Kuhn, one of the original AGPL authors. ONLYOFFICE contends the license is indivisible: accept it wholesale with all additional conditions, or you have no right to use the code at all.

Alongside the legal dispute, ONLYOFFICE terminated its commercial partnership with Nextcloud, which had been active for eight years and allowed users to edit documents directly from within Nextcloud Hub.

The Format Question

The Document Foundation, the organization behind LibreOffice, weighed in as well. The tone was supportive, but the question raised is uncomfortable: what is Euro-Office’s native format? The launch announcement never mentions ODF, instead promising full compatibility with Microsoft formats. As TDF notes on its blog, compatibility with OOXML and digital sovereignty are not the same thing. OOXML is a standard designed, controlled and managed by Microsoft. Building a European alternative centered on that format means moving the server to Europe while keeping the architectural dependency on Redmond.

TDF isn’t asking Euro-Office to drop proprietary format support, something LibreOffice has always done for practical reasons. The question is whether ODF, an ISO standard developed outside any corporation’s control and already mandatory in some European jurisdictions including Germany, will be the format European public administrations use to create and exchange documents. This is a distinction Euro-Office will need to settle before its architecture hardens.

The legal dispute will drag on, and the issue at its center matters beyond this project alone: whether additional conditions ONLYOFFICE added to its AGPLv3 variant are binding on forks is a question affecting the entire open source ecosystem. Until a court rules, both sides have solid legal arguments. Meanwhile, Euro-Office faces the task of building developer momentum and convincing European public administrations of its reliability, all while dealing with a dispute that began on day one.