The planned Euro-Office – the European open source alternative to Microsoft Office, which is being developed by Nextcloud, IONOS and other partners – is already embroiled in a licensing dispute before the first stable release. OnlyOffice, whose source code serves as the basis for the fork, is accusing the project of license violations and has now even suspended its long-standing partnership with Nextcloud.
What is Euro-Office – and why is OnlyOffice affected?
Euro-Office was presented to the Bundestag in Berlin on March 27, 2026 by a consortium consisting of IONOS, Nextcloud, EuroStack, XWiki, OpenProject, Proton, Soverin, Abilian and BTactic. The aim is to create a browser-based, collaborative office suite under European control that will serve as a sovereign alternative to Microsoft Office – especially for public authorities and companies that value digital sovereignty.
Technically, the consortium is not starting from scratch: A fork of OnlyOffice’s open source code was used as the basis. OnlyOffice is an office suite from the Latvian company Ascensio System SIA, which enables word processing, spreadsheets and presentations in the browser and is known for its high compatibility with Microsoft formats (DOCX, XLSX, PPTX). A first stable release of Euro-Office is planned for summer 2026; a tech preview is already available on GitHub.
OnlyOffice: License terms were not adhered to
Shortly after the announcement of Euro-Office, OnlyOffice responded with an official blog post. OnlyOffice is distributed under the GNU Affero General Public License v3 (AGPL v3) – supplemented by additional conditions that have been anchored in Section 7 of the license since May 2021. These require, among other things
- the retention of the OnlyOffice logo in derivative works (Section 7(b))
- correct attribution of the original technology
- full compliance with all open source distribution obligations
- refrain from using the OnlyOffice trademarks (Section 7(e))
According to OnlyOffice, Euro-Office ignores precisely these additional conditions. A lawyer quoted by the company emphasizes: The AGPL v3 does not allow selective use – anyone who wants to use the software must either accept all conditions including the Section 7 supplements or simply receive no rights of use. Anyone who classifies these conditions as “unenforceable” does not change their legal character.
OnlyOffice demands that Euro-Office immediately and fully comply with all license terms – including the retention of branding, logo and source citations.
Nextcloud and IONOS disagree
Nextcloud and IONOS take a fundamentally different view of the situation. Nextcloud told heise online that forks are a central component of the open source ecosystem and are expressly intended to enable further development and alternative governance models. The legal classification is transparently documented in the project’s public GitHub repository.
Nextcloud relies on prominent support: The Free Software Foundation (FSF), which is considered the guardian of the AGPL and GPL licenses, shares this view. Furthermore, the situation has been discussed with Bradley M. Kuhn – the inventor of the AGPL license – who, according to his own statement, fully supports Nextcloud’s legal opinion. IONOS expressly agrees with Nextcloud’s statement.
OnlyOffice terminates 8-year partnership with Nextcloud
The dispute has already had concrete consequences: OnlyOffice has suspended its long-standing partnership with Nextcloud. As Neowin reports, the eight-year partnership enabled Nextcloud users to edit Office documents directly in their own Nextcloud instance – a feature that was particularly popular with self-hosters.
OnlyOffice accuses Nextcloud of repeatedly breaking its trust as a partner in the past – for example by trying to poach OnlyOffice employees and influencing customers. However, the Euro Office fork without any prior communication was a decisive step too far.
Conclusion: A license dispute with an open outcome
The OnlyOffice vs. Euro Office dispute is more than just a technical licensing conflict – it touches on fundamental issues relating to open source governance, software sovereignty and the limits of copyleft licenses. Whether OnlyOffice’s AGPL v3 additional terms are actually legally enforceable or whether Euro-Office was allowed to effectively remove them may only be clarified in court.
For Nextcloud users who previously relied on the OnlyOffice integration, the suspended partnership could have consequences in the medium term. Euro-Office is set to replace the previous Collabora component in Nextcloud anyway – the schedule and further development are now likely to be under particular scrutiny.
