Category: Standards

There is a sophisticated mechanism by which proprietary technology ecosystems maintain their grip on users and institutions, even when those users and institutions believe they are making free choices, using open standards, and building independent digital infrastructure.

The mechanism does not work through force, but through a subtler and more durable strategy: the layering of dependencies, in which each layer obscures the one beneath it, so that when the system fails the apparent cause is something other than the real one.

It is a structural pattern with identifiable components and predictable failure modes, and with a single political consequence: the systematic attribution of interoperability failures to open alternatives rather than to the proprietary dependencies that actually cause them.

Understanding all of this is essential for anyone working on a genuine interoperability policy, because without it even the best-intentioned policy interventions address the visible symptom while leaving untouched the larger problem of the underlying architecture, which goes on working exactly as designed.

The perception of malfunction

Let us start from the user’s experience, because this is where the political damage occurs.

A document is created in Microsoft Word and sent to a colleague who uses LibreOffice on a Linux desktop. The colleague opens the file. Something is wrong: a table has shifted, the text has reflowed, a font looks different, the page breaks have moved.

The experience is familiar to millions of people in institutional settings that have adopted, or are considering adopting, open source software. It is the experience that generates the helpdesk tickets, the emails of pure frustration to the IT department, the conversations that end with “can you just send me a PDF?”, and the broader sentiment, consolidating over time, that open source software is not ready for professional use.

What is the cause of this failure? Users will blame LibreOffice, IT managers will blame format incompatibility, policymakers will blame the immaturity of open standards.

These are all wrong answers. Or rather, they are all answers to the wrong question, because they describe where the failure manifests rather than where it originates.

The actual cause is a set of interdependent technical systems, each contributing a different failure mode, all producing a single visible result.

The format contains proprietary structures that only Microsoft’s implementation handles correctly. The rendering introduces platform-dependent variations that the format specification does not control. The proprietary fonts cannot be legally bundled with open source software.

Three distinct failure modes producing the same symptom, and equally invisible to the user, who perceives only that things worked in Word and do not work in LibreOffice.

This is the architecture of layered dependency. Each layer absorbs the causal chain and emits a different signal, one that points toward the open alternative.

Layer One: the format and its hidden features

The first layer is the most discussed and the most politically visible: the document format. The conflict between ODF and OOXML has been extensively documented, litigated within standards bodies, and debated in national parliaments and in the European institutions.

But even within this well-mapped terrain, it is worth clarifying the specific mechanism of obscuration at the format layer.

OOXML, the format Microsoft Office produces by default, exists in two conformance levels. Strict is a reasonably clean specification. Transitional is something categorically different: a format designed to encode the accumulated behaviour of earlier Microsoft Office versions, preserving decades of proprietary implementation choices as normative elements of an apparently open standard.

OOXML Transitional includes VML — Vector Markup Language, a proprietary drawing format from the late 1990s that predates and contradicts the DrawingML system defined elsewhere in the same specification.

It includes references defined as “as in earlier versions of Microsoft Office”, which make sense only if one has access to those earlier versions and to their undocumented implementation details.

It includes extensions that allow Microsoft to embed proprietary functionality in documents, invisible to non-Microsoft implementations, and capable of causing silent rendering differences ranging from minor visual variation to complete layout failure.

Crucially, OOXML Transitional is what Microsoft Office produces by default.

Every time a user saves a Word document without selecting a different format, they produce a file optimised for the Microsoft ecosystem and subtly hostile to every other.

Users do not know this is happening, because the choice is made for them at the format level, and when the document fails in LibreOffice, the format layer’s contribution to that failure is invisible. The user sees a rendering problem, not a format problem.

This is the first layer of obscuration: proprietary format constructs masked by the label “industry standard”, producing errors that appear to be implementation shortcomings in the receiving software.

Layer Two: rendering and its unspecified behaviour

The second layer is less discussed, less politically visible, and for these very reasons more durable as a source of interoperability failure: text rendering.

Document format standards specify content. They define what a document contains: text, structure, logical relationships, embedded objects, and formatting instructions.

What they do not specify, and what none of the major document format standards has ever specified, is how that content should be rendered. The translation of encoded content into visible glyphs on a screen or a page is left to the implementation, and different implementations make different choices.

These choices operate across several subsystems.

Shaping engines — the software components that translate sequences of Unicode characters into sequences of glyphs, and that handle the complex rules of scripts such as Arabic, Devanagari and Thai — differ by platform.

HarfBuzz, the open source shaping engine used by LibreOffice and by most Linux applications, produces correct, standards-compliant output, but that output may differ in detail from Windows’ Uniscribe or DirectWrite engines, particularly for complex scripts with context-sensitive glyph selection.

The differences are almost always invisible for Latin text, but for the non-Latin scripts used by a significant portion of the European public sector and citizenry, they can be significant.

Hinting interpretation varies across rendering engines. Fonts embed hinting instructions — algorithms that adjust glyph outlines for crisp display at low screen resolutions — but those instructions are interpreted differently by different renderers.

A font optimised for Windows’ GDI rendering engine may display with different weight and spacing under FreeType on Linux, even at identical sizes.

The differences are minute for any single character, but they affect the perceived quality of the text and contribute to the general impression that open source environments are slightly less polished.

Line-breaking and justification algorithms are the most significant source of rendering variation and the most direct cause of document reflow.

The algorithm that determines where to break lines — how to distribute words across a line of a given width, whether and how to hyphenate, how to handle justified text — is an implementation choice that no format specification regulates.

Microsoft Word’s line-breaking algorithm is proprietary and undocumented, and it is very different from LibreOffice’s. Both are legitimate implementations of the same function, and they can produce different line breaks; different line breaks mean different page breaks; and different page breaks mean that a document paginated in Word will not be paginated the same way in LibreOffice.

This is not a defect in implementation quality, but the normal and predictable consequence of differing rendering choices that document format standards do not define. And it produces errors that are invariably attributed to the software receiving the document, because that is where the visible difference appears, rather than to the specifications that are their cause.

The rendering layer is the most technically complex component of the layered dependency and the hardest to address, but it is also the layer that most clearly reveals the dimensions of the problem: an error generated by a different choice made by two projects, attributed solely to the open source software, on the basis of an entirely unjustified, almost faith-based trust in the quality of the proprietary software.

Layer Three: fonts and the dependency on proprietary resources

The third layer completes the picture and, in many practical settings, causes the greatest damage: fonts. Here we will not analyse font-level lock-in as such, but will instead explain how the font layer operates within the layered dependency model.

Fonts interact with both layers above. At the format level, fonts appear as named references: a document declares that the body text is set in Calibri and the headings in Cambria. If those two fonts are not available on the receiving system — and this is the case on every system for which a licence for the proprietary fonts has not been acquired — the software must substitute them.

Substitution changes the metrics, and the metrics in turn change the geometry. Altered geometry produces reflow, broken layouts, forms overflowing their margins; and here too the failure is attributed to the application receiving the document.

At the rendering level, fonts interact with the shaping engine, the hinting system and the antialiasing pipeline in ways specific to each font’s design and embedded instructions. A font optimised for the Windows rendering stack will display differently under FreeType, even before any substitution occurs, and this contributes to the overall visual divergence between environments.

What makes the font layer particularly effective as a lock-in mechanism is the combination of legal unavailability and the user’s lack of information. The proprietary fonts at the heart of the problem — Calibri and Cambria, and before them Arial and Times — are not available under any kind of open source licence.

This is a legal constraint that open source software cannot overcome, but one that users perceive not as a licensing problem but as a software problem — not as the consequence of a strategy but as proof that open source software cannot handle ordinary documents.

Only Aptos, the latest of Microsoft’s proprietary fonts, is released under a partially restrictive licence, since it ties use to a download from Microsoft’s site. It can therefore be installed by Linux users too, and used legally, but this has not been communicated widely enough, so the lock-in mechanism is only reduced, not eliminated.

Why “invisible” is the key word

Each of the three layers would be a manageable problem if it were visible, and if users had the chance to see clearly that the error originates in the proprietary format, or in the insufficient rendering specifications, or in the proprietary font. Visible problems can be addressed and solved on the basis of accurate diagnosis and targeted intervention.

The strength of this scheme lies in its obscurity. Each layer acts as a signal re-encoder: it takes the output of the layer beneath it and re-emits it as something that looks like a different kind of problem.

So the dependency on proprietary fonts produces an error that looks like a software rendering issue; the rendering problem produces an error that looks like an implementation shortcoming; and finally the proprietary format structure produces an error that looks like a failure to comply with standards.

By the time the error reaches the user, its origin is completely obscured, and responsibility is systematically redirected to the last element in the chain: the open source software, which was merely trying to display a document designed to defeat it.

This is not a coincidence arising from poor design.

Software that generated random errors would be a problem for the company that developed it, because user frustration would flow back toward the originating software.
A system that generates errors at the boundary with competitors, in such a way that they are always attributed to those competitors, is a competitive asset.

Here the question of intent matters less than the question of structure: whatever the motivation behind the original design decisions, the resulting architecture functions as a constraint, and its effects are observable and measurable.

How policy responded, and where it failed

The policy response to document lock-in has concentrated on the format: mandating the use of ODF and open formats in public procurement, and guaranteeing that government documents can be created and consulted without the use of proprietary software. Unfortunately, these interventions have almost never been paired with penalties to enforce compliance, and the rules have often been ignored.

Moreover, these format mandates have not addressed the use of proprietary fonts in document templates, so by fixing only the upper layer they leave the lower one exposed and fully operational, where it is less visible and less politically salient, and therefore more durable.

Documents continue to fail at the boundary with open source software, and users continue to blame the latter. The political will behind the format mandate is progressively eroded by user complaints about interoperability problems, which seem to contradict the promise of the open, standard format mandate itself.

An institution that deploys LibreOffice but fails to address rendering consistency — allowing a mixed infrastructure of Windows and Linux systems to exchange documents without recognising that rendering variation is not a software defect — risks creating an internal interoperability problem that could be used to justify a return to monoculture.

The rendering layer has received almost no policy attention. No major digital sovereignty framework specifies rendering-fidelity requirements. No procurement standard defines conformance in terms of visual consistency across implementations.

The tools to address this problem — reference rendering implementations, rendering test suites, fidelity benchmarks — exist only as prototypes or proposals, and have not been integrated into any serious policy framework.

Knowing this pattern is a political act

The invisible layering of dependencies is a pattern born of nearly fifty years of unregulated evolution of personal productivity software, and one that threatens to make the path toward digital sovereignty extraordinarily complex.

It matters to give the pattern a name, so that it can be used in policy discussions, in parliamentary questions, in procurement specifications and in the public debate on digital sovereignty, at every level, including by the media.

The invisible layering of dependencies connects phenomena that do not appear to be related — document format incompatibilities, rendering variation, font substitution failures — and shows that they are expressions of the same underlying architecture.

Once these phenomena are seen as a pattern rather than as isolated technical problems, an appropriate policy response becomes clearer, because it is not enough to fix a single layer and mandate a single standard — even though that is a fundamental first step.

It is necessary to make all the dependencies legible and to integrate them into interoperability policies that address format, rendering and fonts explicitly and specifically, with enforcement mechanisms applying to all three layers.

The open source and open standards community has built the technical foundations for genuine interoperability: open formats are mature and solid, open source applications are fully up to the task, and there are hundreds of openly licensed fonts, many of them metric-compatible with the proprietary ones.

The architecture of lock-in does not persist because the alternatives are inadequate. It persists because policy has not yet learned to look beyond the visible surface of format conformance and to recognise the underlying layers where proprietary dependencies go on operating — invisible and ignored — doing the work they were designed to do.

Any other choice is a choice of dependence on a single vendor

Digital sovereignty begins with the document format. Everything else – server location, hosting jurisdiction, procurement clauses – is downstream of this single decision. If the format is standard and open, the user controls the document. If the format is proprietary the vendor controls it, even when the file sits on the user’s own hard drive.

This is why LibreOffice, and its derivatives such as Collabora Office and Online, are today the only legitimate choice for governments, supranational bodies, businesses and organisations that want to protect the digital freedom of their users. Only software based on the LibreOffice source code – the LibreOffice Technology – uses ODF as its native document format. Every document saved, stored, retained and exchanged in ODF remains the exclusive property of its author, and remains so over the years.

ODF – Open Document Format, as the name says – was designed and developed in accordance with the characteristics of a true open standard: clearly documented, transparently developed by an independent body, properly versioned, built on existing standards, and stored in XML files that any user can read.

None of this applies to OOXML. The name is itself an oxymoron: XML stands for eXtended Markup Language, which is open by definition, but OOXML’s syntax is so complex that it is unreadable even to advanced users. The format was deliberately designed to become a sophisticated lock-in tool at a moment when Microsoft’s other strategies had already been uncovered and analysed.

The Transitional/Strict bait-and-switch

OOXML was approved as an ISO standard through a process that was an affront to transparency, ethics, common sense and respect for users. The format is documented in a way that discourages consultation – over 7,500 pages – and is developed by Microsoft behind closed doors in Redmond.

It is not versioned. It uses no independent standards. On the contrary, it relies on proprietary Microsoft formats wherever possible, in some cases formats that Microsoft itself had deprecated because the market rejected them. It is not even compatible with the Gregorian calendar. The XML schemas are nearly absurd in their complexity.

The bait-and-switch worked like this: “I swear it will be Transitional until 2010, very proprietary and very little of a standard, and after that only Strict, not very proprietary and very much a standard.”

The catch: Strict never materialised in practice. For years it lingered as a last-resort option that no one was meant to use, and it has now disappeared from the Save As options altogether. The standardised version of OOXML – the one ISO was told would become the real format – no longer exists as a user choice. Only Transitional remains.

A pity, because we would have had a laugh with Strict’s bugs. Excel has a thing for getting dates wrong (the (in)famous 1900 leap-year bug, inherited from Lotus 1-2-3 and never fixed), and when Excel gets dates wrong, no other software does it worse.

The political consequences

All of this is hard to grasp by looking at what happens on screen, because the document seems entirely harmless in its apparent simplicity. And yet all of it has been documented in detail since OOXML was first introduced, by independent experts who should have been heard, both by ISO and by those working in advanced technology.

Instead, ISO bought the Transitional/Strict story. And once ISO believed it, governments and politicians believed it too, rushing to adopt OOXML as a document format for fear that Bill Gates and Steve Ballmer might take offence and act accordingly.

In doing so, they placed citizens’ private data in Microsoft’s hands and reinforced a monopoly that was already evident before OOXML’s arrival, and that has become increasingly difficult to dismantle ever since.

The Microsoft ecosystem played its part in all this, and partner companies – SAP foremost among them – have always done everything in their power to push their users toward OOXML for data exchange, openly obstructing the use of the standard ODF format. An uneven struggle, by design.

Worse still, with just a few exceptions, even those who by virtue of their expertise should have recognised OOXML as the cornerstone of Microsoft’s new lock-in strategy fell for it. Some still write today: “we have to accept it, OOXML is an ISO standard.” This is not a serious position.

It is a deference with no rational basis.

Microsoft’s monopoly position is not founded on technological superiority but on the strategic foresight of Bill Gates and the lobbying machinery that flowed from it, deployed well ahead of its time.

The same deference has had consequences in the scientific community as well.

The HUGO Gene Nomenclature Committee was forced in 2020 to rename dozens of human genes – including SEPT1 and MARCH1 – because Excel kept silently converting their symbols to dates. Rather than going to Microsoft and demanding a bug fix, scientists preferred to throw years of established nomenclature down the drain to avoid upsetting Redmond. A revealing precedent.

Supporting ODF is not choosing ODF

There is a distinction that needs to be made plainly, because it is too often blurred, sometimes inadvertently, sometimes by design. Supporting a format is not the same as choosing it.

An office suite that saves OOXML by default is not supporting digital sovereignty, independently from the level of ODF support. It is an OOXML suite with an ODF import/export filter, which inherits all the OOXML based lock-in mechanisms: proprietary schemas, vendor-controlled evolution, hidden binary fragments, format-level dependencies on Microsoft’s roadmap.

Digital sovereignty lives at the native-format layer. Support describes what a piece of software can read. Native format describes what it is. The native format determines the legal and technical character of every document the user creates.

A commitment to “improve ODF support” is not a commitment to digital sovereignty. It is a commitment to keep ODF as a guest in someone else’s house.
This distinction matters for any project, coalition, or procurement decision that claims a digital sovereignty objective. The meaningful question is never whether ODF is supported – it almost always is, at some level – but whether ODF is the native format, chosen and committed to as such.

If the answer is anything other than yes, the sovereignty claim is provisional at best.

What digital sovereignty actually requires

The only viable path to digital sovereignty today is to use ODF as the native document format, and OOXML as the interoperability format for exchange with users who – out of lack of information, or pure convenience – continue to use the proprietary format, and share ownership of their own files with the vendor.

Anything else is false digital sovereignty. Control over a document and over the information it contains depends first on the format and only afterwards on the location of the server.

Standard, open format: the user is in control. Proprietary format: the vendor is in control, even if the document sits on a PC on the user’s desk.

This should be self-evident to anyone working in open source software, because it follows directly from its principles.

A proprietary document respects neither Freedom 1 (the freedom to study and modify) nor Freedom 3 (the freedom to improve and redistribute), as it is not not documented in a way which makes the source code readable and it is not developed through a transparent process.

The decision to adopt OOXML as the native format runs counter to the interests of governments, supranational bodies, organisations of every kind and enterprises. But above all, it runs counter to the interests of users as it exploits their lack of information rather than investing in their education and in their digital sovereignty.

The choice of native format is not a technical detail to be deferred or finessed. It is the choice. Any project that treats it as something less is not supporting digital sovereignty. Full stop.

Euro-Office’s announcement – which sees IONOS, Nextcloud and other companies coming together to create a European alternative to office productivity software – has predictably sparked a wave of comments. Most of these focus on the issue of licensing: is the code open source? Who controls the repository? What are the conditions for forking, modifying or implementing it?

While these are all valid questions, they fail to address the most important issue. The fact that almost no one is asking the question that matters tells us something significant about how the debate on digital sovereignty has been framed and who benefits from that framing.

A licence tells you who owns the software, while the format tells you who owns the data

A licence can be renegotiated, modified or updated. The history of FLOSS is full of projects that have changed governance models, divided communities, or changed course under new management. Licence terms are important, but they operate at the level of the software artefact.

The native document format operates at a completely different level. It is the encoding level of every document produced, archived, and exchanged by institutions that adopt the software. It is the invisible structure of administrative memory within which public documents exist for years, or even generations. It is the infrastructure.

If Euro-Office is supplied with OOXML as the default native format – even if it is wrapped in an open licence, hosted on European servers or governed by a European legal entity – every document drafted by public administrations, schools and institutions will be written in a format designed around the behaviour of a single vendor’s application.

OOXML is governed by a specification that is so complex and internally inconsistent that it compromises interoperability. As if that were not enough, it is optimised for backward compatibility with Microsoft Office rather than for seamless exchange between systems.

The licensing issue asks: who controls the code? The format issue asks: who controls the data? These are not equivalent situations. The latter has long-term implications for public archives, administrative continuity, and the practical significance of vendor independence.

For thirty years, the FLOSS and digital rights communities have been working on licences based on the fundamental principle that a licence equals freedom. This work has produced enormous value, but it has also created an unintentional blind spot.

Microsoft has spent decades conducting one of the most effective user education campaigns in the history of the software industry. However, what it has taught is dependency. Consequently, a generation of users, administrators, developers and even FLOSS advocates has grown up treating OOXML documents as the natural unit of document exchange — just like water flowing from a tap. OOXML files are not perceived as a lock-in mechanism, but as normal documents.

This is an incredible strategic achievement. Microsoft has managed to transform a proprietary file format, which was designed to replicate the behaviour of its own applications rather than enable transparent content exchange, into an interoperability standard.

Compatibility with the OOXML format is not viewed as a courtesy to the monopoly holder; rather, it has become a feature that alternative software must provide to prove its legitimacy. Lock-in has been transformed into an advantage: users are not trapped in Microsoft’s format; they are simply using the format that everyone else uses.

The FOSS community, which should be particularly vigilant about such dynamics, has often uncritically accepted Microsoft’s approach. Indeed, when evaluating an alternative productivity suite, the first question is often about the ability to open OOXML files rather than about the native format and whether it enables interoperability. Unfortunately, the alternative is judged according to criteria subtly dictated by Microsoft.

Consequently, format policy is treated as a secondary technical issue rather than the major political issue it really is. Meanwhile, Microsoft has pursued a precise and successful strategy of securing OOXML certification as an ISO standard to define it as ‘open’, while ensuring that licensing issues take precedence over format issues.

The result is that “supporting ODF” has become a box to tick rather than a specific commitment. This explains why all office suites today claim to support ODF. The practical implications of this support – such as whether ODF is the native or default format, or the format in which documents are created and stored without user intervention – are rarely considered, let alone addressed.

The test that matters

Euro-Office presents itself as a genuine European alternative: an infrastructure project for digital sovereignty. This claim deserves to be put to the test in terms of whether institutions will manage to free themselves from Microsoft lock-in, or if they will simply reproduce it under a different banner.

The test is simple and admits only one answer: ODF will be the native format of Euro-Office; the format in which documents are created, stored, and exchanged by default without user configuration or technical intervention.

Not: Euro-Office supports ODF because, in a nominal sense, everything supports ODF. Users can save in ODF format because this is a compatibility feature, not a commitment to true digital sovereignty.

If the answer is yes, then Euro-Office represents a significant structural break with the dominant proprietary format. However, if the answer implies “compatibility”, “user choice”, “transition paths” or “broad format support”, then Euro-Office is, regardless of the licence, a server migration that leaves Microsoft’s lock-in on data unchanged.

Digital sovereignty is not achieved by changing who hosts the software, but by changing the format in which data is encoded. European institutions, public administrations, and civil society organisations considering Euro-Office deserve a direct and immediate answer to this question before making any further commitments.

ODF has to be native, default, and by design.

Since its foundation, the Document Foundation has supported ODF as an open standard for document exchange. ODF (ISO/IEC 26300) is the only document format standard designed from the outset to ensure interoperability, long-term preservation, and total vendor independence.

The announcement of the Euro-Office is welcome news. The coalition is credible, the governance is sound and the timing is perfect. Europe needs office software, and The Document Foundation is delighted to see such significant players allocating resources to make it happen.

However, we have a question. It is not meant to be hostile, but it is the only question that matters.

What is the native document format of Euro-Office?

The press release promises full compatibility with Microsoft formats. We are well aware of the logic behind migration: organisations moving away from Microsoft need to be certain that their documents will survive the transition. But “full compatibility with Microsoft formats” is certainly not a definition of sovereignty, but rather the definition of a different kind of dependency.

OOXML is a format designed, controlled and managed solely by Microsoft. Building a European office suite prioritising compatibility with OOXML means ensuring that the European document infrastructure remains subordinate to architectural decisions made in Redmond. The hosting moves to Europe, but the lock-in remains in Redmond.

The alternative exists, is mature and is a law in several European jurisdictions. ODF, the Open Document Format, is an ISO standard developed through an open and transparent process, which is not controlled or managed by a company. The German Deutschland-Stack has made it mandatory, and the EU Commission has approved it. It is not the LibreOffice format, but a European public good.

The Euro-Office press release does not mention ODF even once.

We are not asking Euro-Office to abandon support for Microsoft’s proprietary format. LibreOffice itself reads and writes OOXML: compatibility is a necessity for users, not an ideological concession. We are asking whether ODF will be the native format, the one in which documents are created, archived and exchanged between European public administrations.

This distinction is fundamental, and the time to define the native document format is now, before the architecture is finalised and the implementations take place. If necessary, we are here to help with the deployment of the ODF standard as native document format.

The coalition has the credibility and resources to build something truly innovative. We hope it will use them to build a project of sovereignty and not merely a tool for server migration, flying a European flag but with a lock-in firmly rooted in Redmond.

The Document Foundation is a non-profit foundation and the home of LibreOffice, the world’s leading open-source office suite. LibreOffice implements ODF as its native format and supports a wide range of document formats, including the import and export of OOXML.