A coalition of more than a dozen European technology companies has developed Euro-Office, an open-source office suite designed to provide a sovereign alternative to Microsoft 365 and Google Docs. The stable version is set for public release on GitHub on June 9, 2026. Billed as a landmark initiative for “digital sovereignty,” the project has already encountered legal disputes with the original code maintainers and fierce debate over document format standards, making its launch far from smooth.
What Is Euro-Office and Who Is Behind It
Euro-Office is a web-based office suite offering document, spreadsheet, and presentation editors with real-time collaborative editing capabilities. The project is led by German cloud hosting giant IONOS and open-source collaboration platform Nextcloud, with contributions from EuroStack, XWiki, OpenProject, Soverin, Abilian, BTactic, Open-Xchange, Office.eu, and other European enterprises and organizations.
Announced on March 27, 2026 in Berlin, the initiative made a technical preview available immediately. The 1.0 stable release will be published on GitHub on June 9, 2026, integrated into Nextcloud Hub 26 Spring, which ships the same day. IONOS Managed Nextcloud customers will be able to install it immediately after launch. IONOS plans to roll it out within its Nextcloud Workspace later this summer, French partner XWiki will follow in Q4, and Netherlands-based Office.eu will adapt its platform sequentially.
The suite prioritizes compatibility with Microsoft file formats (DOCX, XLSX, PPTX) and its user interface is designed to feel familiar to Microsoft 365 users, minimizing the learning curve. Desktop and mobile versions are planned for later this summer, supporting both local storage and cloud synchronization, according to Nextcloud CEO Frank Karlitschek.
The primary target audience is not individual consumers. Administrative agencies, educational institutions, and regulated industries are the core market. “Given the geopolitical shifts of the past year, the need for a trustworthy, fully Microsoft-compatible, and easy-to-use European office solution is obvious,” said IONOS CEO Achim Weiß.
Why Europe Is Moving Now
The driving force behind Euro-Office is the accelerating trend of European “de-Americanization” of technology dependence that has gained momentum since 2025.
France announced in April 2026 that it would transition government agency operating systems from Windows to Linux. The country had already begun replacing Microsoft Teams and Zoom with its domestic platform “Visio,” targeting complete migration within public institutions by 2027. Germany’s Schleswig-Holstein state is in the process of moving from Microsoft Office to LibreOffice, and the Danish government has declared a similar direction. The city of Lyon is progressively shifting from Windows plus Office to Linux and open-source alternatives.
The common thread is “digital sovereignty.” Concerns about storing national data on servers controlled by American companies have intensified under the Trump administration. According to Nextcloud, 2025 was a turning point for the company: leads for its solutions tripled year-over-year, and over two million new sites were deployed.
The Licensing Dispute That Erupted Within Days
Euro-Office is not built from scratch. It is a fork of OnlyOffice, developed by Ascensio System SIA, a company registered in Latvia. Euro-Office’s own GitHub page candidly states that although OnlyOffice is a Latvian legal entity, “almost all of its developers reside in Russia.” The consortium argues that OnlyOffice’s development opacity and geographic risk made forking the only viable path to European control.
The announcement triggered an immediate response from OnlyOffice. Within three days, the company issued a statement arguing that Euro-Office’s removal of additional terms from the AGPL v3 license was legally unfounded. Since May 2021, OnlyOffice had required brand preservation and attribution under Section 7 of the AGPL. OnlyOffice declared that distributing a derivative work without those conditions had no legal basis.
More dramatically, OnlyOffice suspended its eight-year partnership with Nextcloud, cutting off the integration that allowed Nextcloud users to edit Office documents directly in their browser. The company also alleged that Nextcloud had been poaching its staff and contacting its customers. Nextcloud countered that the additional AGPL terms were not legally binding, and Bradley M. Kuhn, the author of the AGPL, publicly stated that he “100% supports” Euro-Office’s legal interpretation.
The dispute was reportedly “resolved” by the end of May. Karlitschek stated that OnlyOffice had requested only attribution and that an agreement had been reached. However, whether the partnership has been fully restored remains unconfirmed.
The Format Debate: OOXML vs. ODF
The controversy did not stop with licensing. The Document Foundation (TDF), which oversees LibreOffice, issued a public letter raising sharp questions about Euro-Office’s document format strategy.
Euro-Office markets “full compatibility with Microsoft formats” as its primary selling point. TDF argues that OOXML (.docx, .xlsx) is a format designed and controlled by Microsoft, and that prioritizing it means “the server may have moved to Europe, but the lock-in remains in Redmond.” For genuine digital sovereignty, TDF contends, the native format should be the ISO-standard Open Document Format (ODF).
Euro-Office’s GitHub does list ODF support, but its FAQ language focuses overwhelmingly on “high compatibility with Microsoft formats” and does not commit to making ODF the primary format. Euro-Office did not respond to TDF’s inquiry. Karlitschek stated in late May that “full ODF support is the top priority for the next release,” but stopped short of declaring it the native format.
Collabora Online, which is based on LibreOffice technology, also cast a skeptical eye, noting that large portions of the Euro-Office codebase still contain Russian-language comments, raising questions about whether the suite can genuinely be called European. The development team has been working to translate hundreds of thousands of lines of comments into English, but that effort is far from complete.
Why Fork OnlyOffice Instead of Building on LibreOffice?
Nextcloud had previously integrated Collabora Online under the name “Nextcloud Office” for years, meaning a working, open-source alternative already existed within the consortium’s own ecosystem. The decision to fork OnlyOffice instead has raised eyebrows in parts of the technical community. The stated reasons include that code contributions to OnlyOffice were “effectively impossible or extremely difficult,” build procedures were “untrustworthy, outdated, or broken,” mobile editing was limited, and management panels were removed without community consultation. The combination of development intransparency and geopolitical dependency on Russia left the consortium with what it saw as no viable option but to fork and bring the code under European governance.
Digital Sovereignty Is a Banner, Not a Destination
The questions Euro-Office faces go beyond licensing disputes and format wars. They cut to the heart of what digital sovereignty actually requires. Moving code repositories to Europe does not automatically confer independence. Storing data on European servers does not alone create autonomy. As long as the file format specification is controlled by Microsoft, any office suite that prioritizes OOXML compatibility remains subject to decisions made in Redmond.
At the same time, pure idealism does not move bureaucracies. European public institutions have depended on the Microsoft ecosystem for decades. Dropping .docx compatibility would raise the migration barrier dramatically. Euro-Office’s emphasis on compatibility is a pragmatic concession to reality — one that may be essential for adoption.
The version 1.0 release on June 9 is only a beginning. There is no desktop application yet, no mobile app, and dedicated hiring for the development team only started in April. The licensing dispute with OnlyOffice has been “resolved” on the surface, but whether the eight-year partnership can be genuinely rebuilt remains unclear. Independently evolving a forked codebase will require years of sustained investment.
Even so, Euro-Office represents the most concrete attempt yet to create a European-owned office productivity ecosystem at scale. Individual municipalities switching to LibreOffice is one thing; an industry consortium pooling development resources and integrating into existing platforms is another order of ambition. The question now is whether the coalition can translate that ambition into a viable, long-term product. Euro-Office will serve as a litmus test for whether Europe’s digital sovereignty push is substantive or merely symbolic.
Reference: Euro-Office Release Announcement (Nextcloud)
