The pursuit of digital sovereignty has driven European institutions to seek alternatives to dominant software providers. One recent initiative, Euro-Office, a collaborative project by Nextcloud and IONOS, aims to provide a self-hosted, web-based office suite for organizations and governments. However, The Document Foundation (TDF), the nonprofit organization behind the popular LibreOffice suite, has raised a critical question: does Euro-Office truly deliver on its promise of independence, or does it merely replace one dependency with another?
What Is Euro-Office?
Euro-Office is a fork of ONLYOFFICE, a web-based office suite that enables real-time collaborative document editing. By offering self-hosting capabilities, it allows European public bodies and enterprises to keep their data within their own infrastructure, avoiding reliance on cloud services hosted outside the continent. The project emerged partly to distance itself from ONLYOFFICE's association with Russia, which raised concerns about data privacy and geopolitical influence. In its launch press release, Euro-Office emphasized its commitment to European values and digital autonomy.
A Fork with a Purpose
However, TDF quickly pointed out a key oversight: the press release made no mention of Open Document Format (ODF) as the native format. Instead, it highlighted compatibility with Microsoft Office formats (OOXML, including DOCX, PPTX, and XLSX). TDF then publicly asked Euro-Office whether ODF would be the default format for documents created and shared among European public bodies. As of now, Euro-Office has not responded to that question.
The Core Question: Which Document Format?
The choice of document format is not merely a technical detail; it has profound implications for digital sovereignty. ODF, which stands for Open Document Format, is an ISO standard (ISO/IEC 26300) that was developed through an open, multi-vendor process. No single company controls ODF, making it a truly neutral format. In contrast, OOXML, the format used by Microsoft Office, is largely defined and controlled by Microsoft. Even if an office suite is hosted in Europe and respects local privacy laws, defaulting to OOXML means that the structure of documents—and thus the ability to read, edit, and preserve them over the long term—remains dependent on decisions made by a U.S. corporation.
TDF's Open Letter and Euro-Office's Silence
In late March, TDF published an open letter to European citizens arguing that true digital sovereignty requires more than just switching software vendors. Real independence, TDF insisted, demands open document formats, open fonts, and continuity of expertise—benefits that do not automatically come with a vendor change. The letter explicitly called on Euro-Office to commit to ODF as its native format. Despite this public appeal, Euro-Office has remained silent on the matter. TDF followed up with a post thanking ODF contributors and subtly criticizing Euro-Office's lack of transparency.
Why Format Default Matters
Euro-Office's GitHub repository does list support for ODF formats alongside OOXML. However, supporting a format and adopting it as the default are two different things. A default setting influences user behavior: if documents are automatically saved in OOXML, users are more likely to exchange files in that format, perpetuating dependency on Microsoft's ecosystem. Conversely, defaulting to ODF encourages the use of a vendor-neutral standard that can be processed by any ODF-compliant application, including LibreOffice, Apache OpenOffice, and others. The distinction is critical for any European institution that genuinely wants to break away from Microsoft rather than simply shifting the hosting location.
Germany's ODF Mandate
Germany has already mandated ODF for its federal bodies through the SAGA (Standards and Architectures for e-Government Applications) standard. This legal requirement means that any office suite used by German public administrations must be capable of creating and consuming ODF documents natively. Euro-Office, if it hopes to serve these institutions, must ensure full ODF compliance. TDF's question is therefore not merely academic; it has practical legal and policy implications.
Implications for European Digital Sovereignty
The debate between ODF and OOXML goes beyond software preferences. It touches on the core of what digital sovereignty means: the ability for governments and organizations to control their own data, choose their tools, and guarantee long-term access to their information. If Euro-Office adopts OOXML as its native format, it may inadvertently reinforce the very dependency it seeks to escape. TDF's call is for Euro-Office to declare its commitment to open standards, thereby setting a clear example for other European projects.
Whether Euro-Office will address this question directly or continue to stay silent, the issue is now in the public domain. As more European countries consider similar mandates to Germany's, the pressure on Euro-Office to clarify its position will only grow. For now, the ball is in Euro-Office's court—and the future of truly sovereign office productivity in Europe may depend on its response.