The Document Foundation Criticizes Euro-Office: Using Digital Sovereignty as a Marketing Tool, but Following Microsoft’s Technological Approach

The Document Foundation Criticizes Euro-Office: Using Digital Sovereignty as a Marketing Tool, but Following Microsoft’s Technological Approach

In a sharp open letter published on the eve of Euro-Office’s launch, LibreOffice’s parent organization argues the new suite reinforces Microsoft’s document lock-in rather than defeating it.

The Document Foundation (TDF), the nonprofit organization behind LibreOffice, published an open letter on June 8, 2026, leveling pointed criticism at Euro-Office — a new European productivity suite scheduled to launch in its stable 1.0 release on June 9, 2026. The letter, authored by TDF co-founder Italo Vignoli, argues that Euro-Office trades on the rhetoric of “digital sovereignty” while adopting document format practices that effectively serve Microsoft’s interests.

Not the First — A Historical Correction

One of TDF’s opening salvos concerns historical precedent. Euro-Office’s backers have promoted it as the “first open-source office suite developed in Europe.” TDF disputes this emphatically: OpenOffice.org, which grew out of the StarOffice codebase developed by the German company Star Division, launched in 2001. LibreOffice itself followed in 2010, when TDF forked the project. Both, TDF argues, represent over two decades of genuine European open-source development — a heritage the Euro-Office marketing narrative erases.

“If we can speak of Digital Sovereignty in Europe today, it is thanks to The Document Foundation and LibreOffice community members at large, who kept the flag of open-source office suites flying when everyone was predicting their demise.” — Italo Vignoli, co-founder, The Document Foundation

The Format Question: OOXML vs. ODF

The heart of TDF’s critique lies in document format strategy. For years, The Document Foundation has been a vocal critic of Office Open XML (OOXML), the format developed and controlled by Microsoft. TDF has argued that while OOXML carries an ISO standard designation (ISO/IEC 29500), Microsoft’s implementation frequently deviates from the specification and introduces undocumented features, creating practical incompatibilities that keep users dependent on Microsoft Office. The open alternative championed by TDF is the OpenDocument Format (ODF), an ISO-standardized format not controlled by any single vendor.

Euro-Office defaults to OOXML as its native document format — a practical concession to Microsoft compatibility that its backers view as essential for real-world adoption in organizations that already run on Microsoft files. TDF sees this as a fatal contradiction: a suite that claims to fight vendor lock-in while defaulting to the format specifically designed to maintain it.

“Euro-Office defaults to the fully proprietary OOXML document format, developed and controlled solely by Microsoft. This makes it a de facto ally of Microsoft in its content lock-in strategy, with control remaining firmly in Redmond and far from Europe.” — TDF Open Letter, June 8, 2026

A Clash of Sovereignty Philosophies

TDF’s critique extends beyond technical standards into a deeper philosophical argument about what “digital sovereignty” actually means. In a separate open letter published in late March — before Euro-Office’s format strategy was confirmed — TDF argued to European citizens that genuine sovereignty requires control over document formats and fonts, not merely a change of software vendor. Switching from a US-governed productivity cloud to a European-governed one while continuing to use Microsoft’s file formats, TDF contends, does not liberate users from Microsoft’s ecosystem; it merely changes the intermediary.

Vignoli’s June 8 letter goes further, suggesting that Euro-Office’s positioning represents “pure opportunism” — riding a political moment that TDF and LibreOffice helped create, without having participated in the long effort to build truly open alternatives. He notes pointedly that many of those now championing digital sovereignty “were silent back in 2006, when the open ISO/IEC ODF standard — the pillar of Digital Sovereignty — was announced.”

Context: A Contested Launch

The TDF letter arrives in a climate of existing controversy around Euro-Office. Since the project’s March announcement, OnlyOffice — whose codebase Euro-Office forked — has raised licensing objections, alleging the fork was executed without respecting its open-source license terms. Euro-Office’s partners responded that direct collaboration with OnlyOffice was not feasible. The format debate, meanwhile, has been simmering since April, when TDF publicly asked Euro-Office which document format it would use as its default and received no response before confirming the OOXML default independently.

Euro-Office’s backers have not yet responded publicly to TDF’s June 8 letter. The broader European open-source community remains divided: some view Euro-Office’s pragmatic OOXML compatibility as a necessary bridge to enterprise and government adoption, while others side with TDF in arguing that true sovereignty is impossible without format independence.

What This Means for European Users

For organizations evaluating office software under the banner of digital sovereignty, the dispute crystallizes a genuine tension. Euro-Office offers familiar Microsoft-like workflows in a European-governed, self-hostable package — a lower migration barrier. LibreOffice offers full format independence through ODF, but requires a more significant adjustment for users accustomed to Microsoft Office. Neither path is without trade-offs, and TDF’s open letter, whatever its competitive motivations, raises questions that European institutions will need to answer as they develop their procurement strategies.