EU Office Suite Fork Sparks Open Source Licensing Dispute: OnlyOffice Demands Nextcloud Restore Removed Branding
A dispute over open source licensing and trademarks surrounding the European office suite project "Euro-Office" continues to escalate. OnlyOffice is formally invoking the terms of the AGPLv3 license, demanding that Nextcloud restore the OnlyOffice brand and related identifiers previously removed from its Euro-Office fork.
This March, several European tech companies, including Nextcloud, created a fork called "Euro-Office" based on the OnlyOffice project, aiming to create a "sovereign office suite" alternative to Microsoft Office. Shortly after its launch, OnlyOffice accused Euro-Office of violating the GNU Affero General Public License version 3 (AGPLv3) by removing its brand and logo during the fork, and subsequently terminated its eight-year partnership with Nextcloud. This partnership previously allowed Nextcloud users to directly call the OnlyOffice engine to edit documents within its interface.
On April 17th, Nextcloud released a detailed legal analysis responding to the allegations, asserting that the Euro-Office fork complies with the spirit and terms of AGPLv3, and criticizing OnlyOffice for setting "proprietary traps" by forcing the retention of the logo, thereby harming users' four fundamental open source freedoms: to run, study, modify, and distribute code. The Nextcloud team also cited the views of Bradley M. Kühn, the original author of AGPL, and attempted to use a "self-cleaning mechanism" within the license terms to counter the additional restrictions imposed by OnlyOffice.
The core of the dispute centers on section 7 of AGPLv3. This section allows authors to add specific additional terms such as disclaimers (7a), retention of legal statements (7b), and prohibitions against false attribution (7c). OnlyOffice previously claimed that its requirement to retain the logo falls under the "author attribution" allowed by clause 7(b). Nextcloud countered that a corporate logo is essentially a trademark, not a simple author attribution requirement, and therefore constitutes a "further restriction" prohibited by the license, triggering the so-called "self-cleaning mechanism" of AGPLv3: as long as the program contains additional restrictive terms, subsequent recipients have the right to remove them. The Free Software Foundation (FSF) offered a similar explanation in a blog post in January of this year, emphasizing that "attribution" should refer to natural person authors, not corporate brand identifiers.
In response to the positions of Nextcloud and the FSF, OnlyOffice recently issued an open letter, stating that the FSF's 2026 blog post only represents its "view" and is not legally binding. OnlyOffice emphasized that the legally binding document is the AGPLv3 text officially released in 2007, and the FSF's subsequent explanatory text is merely a "later interpretation" that cannot be equated with a revision of the license text. Regarding the claim that the logo is a trademark rather than an attribution, OnlyOffice pointed out in its open letter that the AGPLv3 text never explicitly defined the term "author attributions," and that its current licensing practice was established before the FSF's "sudden narrow definition" this year.
In its statement, OnlyOffice said it does not want to dwell on the brand dispute, but proposed a "constructive" solution: modifying the interface and source code of Euro-Office. Citing section 5(d) of AGPLv3, the company explained that even without restoring the specific logo, Euro-Office must provide an easily accessible "About" page that clearly identifies ONLYOFFICE as the original developer and states that the current software is a modified version. In addition, OnlyOffice requires Euro-Office to retain the legal statement of the project source in the source code and to correct the description in public materials (such as the code repository description) to clearly indicate that Euro-Office is a derivative work based on OnlyOffice.
As OnlyOffice, Nextcloud, and the FSF each offer different legal interpretations, this dispute over AGPLv3 licensing and brand ownership has escalated from a simple partner conflict to one of the landmark cases attracting attention from the open source community. Until consensus is reached among the parties, the future direction of Euro-Office, and how similar projects will balance freedom and control when dealing with trademark and attribution terms, remains to be seen.