Technology Archives - TDF Community Blog

Home » Technology

CISA Publishes Open Source Security Guidance: Verifiability Is the Difference

2026-08-04

On 30 July 2026, the United States Cybersecurity and Infrastructure Security Agency published Open Source Software: Security Principles and Practices, a 31-page guidance document for federal civilian agencies. It is available at no cost and marked TLP:CLEAR, meaning it may be shared without restriction.

The document is addressed to US federal agencies, and it fulfils obligations under two executive orders on federal cybersecurity. It covers four areas: using open source solutions, contributing to open source projects, producing open source software, and evaluating open source artificial intelligence models. The observations below concern the first three.

Its analytical content is not jurisdiction-specific, and public administrations elsewhere — including in Europe — will find that it articulates, in the vocabulary of risk management, several positions that the open source community has been arguing for two decades.

What the guidance actually says

The central claim is more precise than the headlines suggest. CISA does not assert that open source software is more secure than proprietary software. It states that OSS is “no more or less risky than other software,” and locates the difference elsewhere: with open source, an organisation can assess code quality and security directly, rather than relying solely on vendor assurances.

This is a claim about verifiability, not about defect rates. It is also the more defensible claim, and the more consequential one for procurement. An agency evaluating proprietary software is evaluating a vendor’s statement about its own product. An agency evaluating open source software is evaluating the product.

The guidance draws the corollary explicitly. Among the benefits it lists for federal agencies is reduced vendor lock-in: open standards and modifiable code, CISA writes, protect agencies from “proprietary dependency traps.” A national cybersecurity authority has placed lock-in inside a security document rather than a competition-policy one. That is a meaningful shift in where this argument is permitted to live.

The C4 Framework

The most practically useful part of the guidance is Appendix A, which sets out the C4 Framework for assessing whether an open source project is trustworthy. Its premise is that, because contributors may be pseudonymous and are bound by no delivery obligation, trustworthiness cannot be assessed from who produced the software. It must be assessed from how the software was produced — which open source development makes visible in a way that closed development does not.

C4 groups the evidence into four categories:

Codebase — commit recency, known vulnerabilities, dependency currency.
Community — number of maintainers, institutional structure, whether the project sits within a foundation.
Conduct — whether there is a vulnerability disclosure policy, whether code review is required, whether maintainers merge their own commits, the licence, the code of conduct.
Configuration — whether defaults are secure, and what hardening the software supports.

The framework is applied in five steps: identify measurable criteria, determine risk tolerance and weight the criteria, collect observations (with automated tooling where available), evaluate against each criterion, and compare the result to the tolerance.

We would encourage public administrations to apply this framework to LibreOffice. Every category can be answered from public evidence: a continuous commit history since 2010, a published security policy and disclosure process, mandatory peer review, an OSI-approved licence, a documented code of conduct, and a governance structure — The Document Foundation, a German Stiftung with an elected Board of Directors — that is a matter of public record rather than of assertion.

We would encourage administrations to apply the same framework to every candidate solution, including proprietary ones, and to note which questions can be answered and which cannot.

Contributing, and the support question

The guidance also addresses a question that public administrations regularly raise about open source adoption: who is responsible for fixes. CISA’s answer is that no single entity is obliged to provide them, and that agencies should therefore plan accordingly — assigning internal staff, contracting third parties, or both — while following two principles in dealing with upstream projects: collaborate rather than demand, and push fixes upstream.

This is a fair description of how the LibreOffice ecosystem works. Support, long-term maintenance, and custom development are provided by certified developers and certified migration professionals, whose contributions return to the shared codebase and benefit every other deployment. The guidance is right that this requires organisations to plan for it. It is also right that the resulting improvements are shared rather than captured.

CISA further notes that where a project becomes unmaintained, an organisation may as a last resort take over a fork. This option has no equivalent in proprietary software, where end of support arrives on the supplier’s schedule and offers no remedy at all.

A note on scope

The document does not name any product. CISA states explicitly that it does not endorse commercial entities, products, or services, and nothing in the guidance should be read as an assessment of any particular software. What it provides is a set of criteria. The observation that LibreOffice satisfies them is ours, and rests on evidence that anyone may check.

Open Source Software: Security Principles and Practices is available from CISA: https://www.cisa.gov/resources-tools/resources/open-source-software-security-principles-and-practices

CISA’s announcement: https://www.cisa.gov/news-events/news/cisa-guide-helps-federal-agencies-securely-and-effectively-use-open-source-software

New LibreOffice extension: Impress Remote

2026-08-042026-08-04

LibreOffice extensions are optional, third-party addons for the suite, that add extra functionality. Bora Yarkın has been working on a new extension for LibreOffice Impress, so let’s hear from him about it…

Tell us about it!

The extension lets you control a LibreOffice Impress presentation from your phone or any other device with a modern web browser.

When you start the remote, LibreOffice displays a QR code. Scan it with your phone and the presentation starts from the first slide. The phone interface then shows the current slide, presenter notes, elapsed time and navigation controls.

I tried to make the process as simple as possible: no separate mobile application and no manual pairing codes.

The remote can be opened from the Slide Show menu in LibreOffice’s top application menu bar—the menu alongside File, Edit, View and the other main menus.

This should not be confused with the Slide Show tab inside LibreOffice’s Tabbed user interface. LibreOffice’s UNO extension API does not currently let me add commands to that built-in tab. When using the Tabbed interface, the remote commands are therefore available under the Extensions tab instead.

The extension currently provides several connection modes:

Local network: The phone connects directly to the computer running LibreOffice through its local IPv4 address. This is the main mode and the one I have tested most thoroughly.
Direct IPv6: Works similarly, but uses an IPv6 connection. It is still marked experimental because my home internet connection is currently the only IPv6 network I can properly test with.
Relay server: A small Python service that can be hosted on Linux or Windows. It is useful when the phone and computer are on different networks or when direct connections are blocked by carrier-grade NAT, firewalls or other network restrictions. It also supports multiple connections, so an organisation can host one relay server on its own infrastructure.
LocalTunnel: An experimental fallback that creates an outbound connection through the LocalTunnel service. I consider this a last-resort option when the other connection methods are unavailable.

The compatible relay-server package is bundled with the extension. It can be downloaded or extracted directly from the Remote Settings window by selecting “Get Relay Server”. The package includes the required documentation and setup instructions.

To install the extension, download the .oxt file from the LibreOffice Extensions website or GitHub and open it with LibreOffice. It can also be installed manually through Tools > Extensions. After installation, restart LibreOffice if requested.

The extension includes translations for more than 100 languages and automatically follows LibreOffice’s interface language. English and Turkish are the two languages I have personally checked. Many of the other translations were created with ChatGPT, so I cannot guarantee their quality and would be very grateful for corrections from native speakers.

Why did you create it, and what was the process like?

The original inspiration came from Apple Keynote.

When Keynote is installed on both a Mac and an iPhone, the phone can be used to control the presentation while also displaying presenter notes. That feature completely changed the way I give presentations.

Over time, my slides became more professional and less text-heavy. Instead of putting everything on the slide, I started using the presenter notes almost like a teleprompter, with the text I actually planned to say. This helped move the audience’s attention away from reading the screen and back towards me.

That workflow worked perfectly for a long time, but I never really liked Keynote itself. I could not get used to its interface, and Apple’s decision to introduce paid features was the final reason for me to start looking for an alternative.

There were already several possible solutions, but none of them really worked for me.

LibreOffice previously had its own Impress Remote mobile application, but it has not been maintained for a long time and is no longer practical on many current devices and systems.

Browser-based presentation platforms can offer remote-control features, but I did not want my main presentation workflow to depend on an online service. They also do not offer the same flexibility as a full desktop office suite.

Microsoft Office was another possible option, but I am not a fan of Microsoft’s current direction, particularly the increasing integration of Copilot throughout its products.

OnlyOffice Desktop Editors is a good alternative and I used it for a while, but I encountered several bugs and eventually needed features it did not provide.

That brought me to LibreOffice, which I now find more useful and capable than the other office suites I tried. The only thing missing was the remote-presenter experience I had become dependent on with Keynote.

So I decided to build it myself.

I work mainly in IT and I am familiar with programming, but I would not describe myself as an advanced software developer. Before starting this project, I knew almost nothing about LibreOffice’s UNO API.

I began with ChatGPT. I defined the architecture, features, user interface and constraints myself—including requirements such as localisation being mandatory—and used AI to help me understand UNO and implement the code. The result turned out much better than I expected.

The extension was originally only a personal project. The first version was very basic; the web interface did not even have a back button. I had no intention of publishing it. Once it started working reliably, however, I realised that other LibreOffice users might want the same experience. I decided to take the project more seriously and turn it into a complete extension rather than something that only worked on my own computer.

That meant adding a more polished phone interface, connection settings, QR-code generation, IPv6 support, the relay server, LocalTunnel support, localisation, documentation, error handling and packaging.

Publishing it on the LibreOffice Extensions website was much easier than I expected. I created an account, created the project page, entered the information, uploaded the package and submitted it. After roughly a day of review, the extension was available publicly.

How can people help with testing and further development?

The source code and issue tracker are available on GitHub. The repository includes templates for bug reports, feature requests and pull requests.

My main development and testing setup is macOS with an iPhone. I have also tested the extension on Windows and Linux, but those tests were performed under less-than-ideal conditions, including virtual machines, Remote Desktop sessions and a headless Windows Server installation.

Because of that, testing on real Windows and Linux desktop systems would be especially useful.

The areas where community help would be most valuable are:

Testing different LibreOffice versions
Testing Windows, Linux and different macOS versions
Testing Android devices and different mobile browsers
Testing IPv6 connections between genuinely separate networks
Testing the relay server in real-world and organisational environments
Testing unusual firewall, VPN, NAT and carrier network configurations
Reviewing and correcting translations
Improving the documentation
Reporting bugs and suggesting features
Contributing fixes through pull requests

The local IPv4 mode has been tested extensively across different local networks, internet providers and VPN configurations. The IPv6, relay-server and LocalTunnel modes need broader community testing before I would consider them fully proven.

When reporting a connection problem, including the operating system, LibreOffice version, browser, phone type, selected connection mode and basic network configuration would help enormously.

The project started because I wanted this functionality for myself. Now I would like to make it reliable enough that other LibreOffice users and organisations can confidently use it for their own presentations.

Why OOXML-Based Suites Handle ODF Badly

2026-07-312026-07-31

The question arises naturally for anyone who chooses the standard format over the proprietary one: why do office suites that use OOXML as their native format handle ODF in ways that range from poor to appalling?

The two most obvious answers are these: vendors have neglected the format, treating it as an afterthought, or they are quietly working to discredit the very idea of transparent interoperability, through support so bad that it demonstrates the format “does not work”.

Both answers are too simplistic. The reality is that three distinct mechanisms are at work, applying to different vendors in different proportions and ultimately converging on the same outcome.

A challenge that is not a challenge

Reading and writing ODF faithfully, in isolation, is genuinely feasible: the format is completely and openly specified, and there is no equivalent of OOXML’s notorious legacy compatibility flags, which refer to undocumented behaviours of old Microsoft products that only Microsoft can reproduce.

A competent development team is able to implement ODF correctly on the basis of the ODF specification alone.

An office suite, however, does not implement a format in isolation: it has an internal, in-memory representation of the document. Loading a document is a mapping into that representation, and saving a document is a mapping out of it.

Fidelity is greatest when the internal model is congruent with the document format. LibreOffice’s model is essentially ODF, which is why, in this context, ODF is genuinely native.

When a suite’s internal model has the shape of OOXML, ODF stops being native and becomes an external import that must be converted to and from a representation built for a different format.

Take an ODF feature that OOXML lacks: the ODP field that displays the total number of slides. The instructive part is that the information itself is not missing from a PPTX file. The package enumerates every slide, and the count is available to any program that opens it. What OOXML provides no way to express is the statement that this number is the total. There is a field for the current slide number and none for the count, and Microsoft’s own guidance is to type the figure into a text box and keep it up to date by hand, which is a precise description of not having a field at all. Every published workaround is a macro or an add-in that computes the number once and writes it out as fixed text.

So when an ODP file carrying that field is opened in an OOXML-based editor, what is lost is not the data but the instruction. The number survives. The fact that it was calculated does not, and from that moment the document no longer knows how long it is.

The reverse direction fails more quietly, and therefore worse. A slide count exported from Impress to PPTX has to be written out as fixed text, so the presentation is correct on the day it is converted and wrong the first time a slide is added or removed. A number that has stopped being calculated but still looks plausible is more damaging than a visible gap, because nothing in the document signals that it needs checking.

An ODF-based editor handles the reverse case in an entirely different way. When it encounters a feature present in one format and absent from the other, it sets the data aside rather than discarding it, and restores it when the document returns to OOXML. In LibreOffice this mechanism has a name, the grab bag, and it is a documented part of the import filters rather than an incidental behaviour.

The difference does not lie in the quality of the import filter, but in the fact that the architecture was designed to hold the meaning of the other format.

This matters, because it means that poor ODF support in OOXML-based suites is largely overdetermined before the question of motive even arises. The difficulty is not absolute, but relative to the architecture the vendor has chosen.

Three mechanisms

First: the bet on a reference format. Some suites do not consider ODF at all, because they have built their value proposition on the other format.

OnlyOffice is the clearest case, because it was built around OOXML and converts every other format into that model, so ODF is a second-class import and export format by design.

WPS Office is software created to open docx, xlsx and pptx files faithfully. Its ODF functionality derives from the add-in of Microsoft’s own OpenXML project and was integrated into the application only in May 2022, as a conversion layer written for ODF 1.1, which is to say for the 2007 revision of the standard. Fifteen years of delay were built in on the day of release.

Google Workspace is a variant of the same logic rather than an exception to it. Its internal model is neither ODF nor OOXML but a proprietary web representation, and both formats reach it through a conversion layer. For a public administration the consequence is identical: the open standard is an export target, not the substrate the software thinks in.

For these vendors, ODF was never part of the strategy. Their proposition is to open Microsoft documents in something other than Microsoft Office, and to make them look right, so poor ODF support is the direct consequence of the strategy.

Second: deliberate underinvestment. This is probably a cause that cuts across the whole office suite sector. Although ODF is easier and cheaper to implement correctly, the process still involves development, quality assurance and maintenance costs and timelines, in order to keep pace with a continuously evolving standard.

If a vendor’s users mostly exchange docx files, the marginal commercial value of excellent ODF support is close to zero, so ODF is first implemented at the minimum level and then quietly left to rot.

The perception that ODF support does not matter is itself a consequence of a single company’s market dominance, and its effect is twofold. Lock-in becomes a software feature that the market regards as entirely normal, and ODF acquires a reputation for fragility that no deliberate campaign was required to produce.

Third: deliberate disqualification. This mechanism is real, and it concerns Microsoft itself, with Service Pack 2 for Office 2007. The ODF support it shipped failed in two opposite directions at once.

When reading an ODF spreadsheet produced by another application, Excel silently stripped out the formulas and kept only the last value each cell had held, reducing the document, in Rob Weir’s assessment at the time, to a mere “table of numbers” with the calculation logic gone. When writing, Excel placed formulas in an Excel namespace that was neither the one used by OpenOffice and the other ODF applications nor the OOXML one. Applications that checked the namespace rejected the document outright; those that did not check it displayed a corrupted file showing neither the formula nor the value correctly.

This is a textbook mechanism for discrediting interoperability: meeting a format requirement with an implementation that conforms only on paper and produces visibly broken files, demonstrating to every observer that ODF does not actually work.

At the time, Microsoft argued that the ODF standard did not define spreadsheet formulas, which arrived only with ODF 1.2, and that there was therefore no reference to follow. The argument does not survive Microsoft’s own reply. Responding publicly to Weir, Microsoft’s evangelist Doug Mahugh set the two behaviours side by side: faced with the same unrecognised formula syntax, IBM Lotus Symphony preserved the formula markup, while Excel preserved the cached values. Neither application had a specification to follow. Only one had an architecture with somewhere to put what it did not understand.

It is worth noting what Excel kept. Not the formula, but its last result, which is the same reduction we saw with the slide count, in a different application. A model shaped by OOXML retains the value and loses the computation that produced it, and a document reduced to its last results is a document that has stopped being able to correct itself.

That episode is seventeen years old, and it would be easy to set it aside as history. Microsoft Office today declares support for ODF 1.4. But what improved is the nominal conformance, not the architecture. The internal model is still OOXML, and every ODF document that passes through it is still a translation.

The synthesis

Poor ODF support is not a technical verdict on the format, but the visible shape of a market organised around the dominance of a single vendor, and that shape did not come about by chance.

For European public administrations, this redefines the practical question, because the interoperability problems they encounter when they try to migrate to the open standard ODF are not caused by ODF, which is entirely ready. They are evidence that most of the available tools were designed to be native to somebody else’s format, and that the one vendor with the power to change this situation has repeatedly chosen not to.

The precarious state of ODF support in the market is not a reason to hesitate over adopting the standard, but the strongest possible reason to mandate it, and to mandate it precisely.

The question that protects a public body’s documents, and its sovereignty over them, is not whether ODF is supported, but whether that support is native, that is, whether the software’s own internal model is the open standard, or the standard is merely a foreign element inside an engine built for something else.

The document format is the substrate of administrative continuity and public memory. Choosing tools for which the open standard is native is not a preference between equivalent options, but the difference between owning your documents and renting access to them from whoever controls the format in which they are actually written.

Web and Mobile Development Strategy Proposal

2026-05-302026-06-02

Executive Summary

This proposal suggests restarting LibreOffice web, mobile, and cloud development by structuring the project into a set of independent initiatives. Each initiative can be pursued separately from the others, and their deliverables will be useful improvements to LibreOffice even without the other components.

• Responsive user interface
• Web distribution based on desktop version using WebAssembly
• Mobile distributions based on desktop version
• Document server and integration
• Client-server collaborative editing

One of the greatest risks to large software projects is schedule slip due to dependencies between components. By structuring the project as independent initiatives with separate deliverables, rather than a single monolithic project, we can reduce that risk. This approach also calls for a high level of code sharing across the desktop, web, and mobile versions, which will reduce both our initial development and long-term code maintenance costs.

The result of this project will be a blended web, mobile, and cloud offering and development strategy, which will signal to the public that LibreOffice is on a clear trajectory toward achieving technical parity with the major commercial office suites. In lieu of invasive first-party cloud service integrations, we will aim to offer server components that are lightweight and inexpensive to host, and make it easy for users to work with multiple server providers.

Please note that this document is intended as a strategy proposal, not as a technical specification or project plan. Technical and planning commentary in this document should be considered speculative. Additional work is needed to prepare concrete implementation plans for each initiative, should we choose to proceed with this strategy.

Market Analysis

Consumers

Due to the nature of our project, we have relatively little visibility into the needs of our end users. We also have limited resources to conduct primary market research, in part out of consideration for user privacy. Most of our institutional understanding of end user needs comes from engaged community members who volunteer their time to advocate for their particular interests, which may not be representative of larger populations.

Rather than investigate the needs of end users directly, we can instead borrow from economics and examine the revealed preferences of consumers: if a great majority of people select one product over its alternatives, ceteris paribus, we may safely assume those people prefer that product. Thus, the features our major competitors use to distinguish themselves can serve as signposts for what users consider when choosing between cloud-enabled office suites.

Service Providers

One special case is the group of users who are invested in deploying and operating cloud-enabled office suites. This category ranges from institutional IT decision-makers, to on-premises cloud software vendors such as Nextcloud.

The Document Foundation has not been previously involved with developing or marketing a cloud-enabled office suite. As a result, we have few direct contacts we can use in order to gather requirements. However, we may be able to draw some conclusions about what this category of consumer wants based on public comments and prevailing economic and regulatory conditions.

For server operators, the world looks quite different today than it did when the LibreOffice project was founded. Application hosting costs have risen dramatically, driven by a complex interaction of increasing energy costs, server component supply chain disruptions, excess demand due to AI speculation, and vendor consolidation. We can no longer expect users to host applications that perform unnecessary computation inside the datacenter, where space, hardware, and energy are all at their most expensive – and are needed for other business activities.

In addition to more immediate financial concerns, software sustainability / “green coding” has continued to develop among policy, government procurement, and investor risk management (ESG) circles. For one concrete example, the 2024 French RGESN V2 (“Référentiel général d’écoconception de services numériques”) mandates software eco-design principles and resource efficiency for certain types of public procurement. Many other jurisdictions are developing similar regulations, including Germany and the UK.

In order for a LibreOffice cloud initiative to succeed, we must at minimum offer software that server operators can afford to host. While these macroeconomic conditions are still evolving, it seems clear enough that service providers will grow increasingly sensitive to operating costs, and will prefer applications that require less energy, bandwidth, and system memory in the short term. As there is currently no energy-efficient cloud office suite based on open document standards, it is possible that open standard adoption will be impaired should we fail to provide one.

Competitors

The cloud-enabled office suite market is overwhelmingly dominated by two competitors: Microsoft and Google. Their products are closed-source, distributed under restrictive terms, lack on-premises hosting [1], and are tied to proprietary document formats. Combined, Microsoft and Google capture roughly 96% of the total addressable market. The remaining 4% is divided among a long tail of small vendors, with office suite products that range from the purpose-built for specific national markets, to nascent general-purpose suites that have yet to achieve product-market fit. Market shares for firms within this 4% long tail are too low to individually estimate with any accuracy.

We are all familiar with this breakdown, but it does not go without saying. It takes conscious effort to maintain a clear perspective about a global market. Due to our history, we have interacted with office suite projects from the long tail of this market more than we have interacted with the market leaders. This history risks leading us to focus on the wrong problems.

In order to achieve the goals of our foundation, we need to reset our expectations. Revealed consumer preferences suggest there are only two cloud-enabled office suites that offer what users need: those of Microsoft and Google. We should aim high, and plan with the intention that we will provide credible alternatives for Microsoft and Google products that comply with our values.

Microsoft 365

Distinguishing features

It is Microsoft Office
Microsoft Office is considered the default office suite by most prospective users, and the Microsoft 365 web offering benefits from this association.

Feature-limited web version with streamlined user interface
Much like their sole competitor, the Microsoft 365 web versions offer a greatly simplified user experience which is optimal for everyday, quick document authoring. The user interface is stripped down, but looks visually similar enough to the desktop applications to be familiar to experienced users.

Full-featured desktop versions available for advanced users
The Microsoft 365 web versions do not replace the classic desktop versions. Both versions are provided to users, and the web version guides users to open documents in the desktop version for editing.

Cross-platform collaboration between web and desktop
Collaboration and cloud features are usable from both the web and desktop versions. Collaboration requires documents to be stored on either OneDrive or SharePoint.

Weaknesses

Web versions are based on a different codebase
Although the Microsoft 365 web applications visually resemble their desktop counterparts, to our understanding they are greenfield efforts. The web versions suffer from interoperability issues with the desktop versions, prompting user complaints.

Web versions are feature-incomplete
The Microsoft 365 web applications are missing features that are present in the desktop versions. Some of these features are obscure, but many aren’t (for example, dragging images to move anchors). The web version compensates for this by offering an easy transition to the desktop version for more intensive editing work.

No on-premises option
Since Microsoft discontinued the Office Online Server, it is no longer possible to host the web version locally. Using the web version requires Microsoft cloud services.

Limited data control
Microsoft 365 allows local and on-premises document storage (SharePoint). However, using collaboration features requires communication with Microsoft cloud services, even if the document is hosted on premises.

Google Workspace

Distinguishing features

Web-native
Google Workspace is a web application. It loads quickly, and the user interface is highly responsive.

Simple, streamlined user interface
As with Microsoft 365’s web versions, Google Workspace offers a feature-limited and streamlined user experience which is optimized for simple document editing tasks.

Ubiquitous
Google Workspace is tied/bundled with Google’s other services. It is automatically available to any user who has a Gmail account. Sharing and collaboration is as easy as sending an e-mail.

Documents aren’t files
Within Google Workspace, documents exist as abstract entities in a persistent cloud. Documents are always stored on the server in Google proprietary document formats.

Disadvantages

No native desktop version
Google Workspace is designed around a persistent internet connection. The primary application is a web application hosted on Google servers. The mobile versions are hosted locally, but have artificially limited offline modes.

Feature set is extremely limited
Google Workspace is missing all but the most trivial document formatting features. Although this is sufficient for many use cases, it is not a complete office solution. In practice, Google Workspace must be supplemented with standalone Microsoft Office licenses in commercial deployments.

No on-premises option
Google Workspace is a cloud-native web application. It was designed around Google’s cloud services, and cannot be separated from them.

No data control
Google Workspace does not allow local or on-premises document storage. Documents cannot be viewed or edited without uploading them to Google’s servers. For regulatory compliance reasons, Google Workspace allows on-premises backup of cloud documents, but there is no official way to restore those backups.

Lessons

We are LibreOffice

LibreOffice is the most successful free and open source office suite. Our brand is valuable, and our user base is dedicated. While we do not have an advantage over Microsoft in this area, this is also not a weak starting position. Many users and organizations will evaluate our offering simply due to name recognition. It is therefore crucial to avoid tying our brand identity to products or technical approaches that do not show clear trajectory toward meeting the needs of users and operators.

Availability rather than interoperability

On the desktop, we have long considered Microsoft Office interoperability a key obstacle for broader LibreOffice adoption. This assumption does not apply to the cloud-enabled segment. Google Workspace has achieved a large market share despite lacking support for Microsoft Office document formats (only lossy import and export). If Google Workspace is not hindered by their Microsoft-incompatible document models based on proprietary file formats, we will not be hindered by ours based on open standards.

With cloud-enabled office suites, document exchange between users of different office suites is achieved by sharing links that can be opened in standard web browsers. This is important to support.

Same code – feature complete

By reusing the existing LibreOffice source code to drive the web version, we can avoid the compatibility issues and feature set limitations present in the major competing products. A feature-limited user experience is then a choice we can allow users to make, rather than forcing it on users due to implementation strategy.

Streamlined web experience available

Both major competitors treat their web versions as a secondary workflow, to be supplemented with a complete desktop office suite. Their user interfaces are optimized for quick viewing and editing, either on a secondary device or while quickly browsing files stored in a cloud storage application. We should consider also displaying such a streamlined user interface, at least by default; both major competitors collect user telemetry, so it is reasonable to suppose their decision was evidence-based.

Cross-platform collaboration between web and desktop

This is a key differentiator for Microsoft 365. We should provide the same capabilities. All cloud-based features should be equally usable from the desktop version as the web version.

Responsive user interface

Users can interact with Microsoft 365 and Google Workspace documents without blocking on client-server communication. Editing is smooth, and has a near-desktop feel. We should aim to provide a similar user experience.

On-premises hosting – no privileged cloud provider

Neither major competitor offers on-premises options for hosting or cloud services. This is an area where we can distinguish ourselves, but it is also a challenge. By privileging their own cloud services, Microsoft 365 and Google Workspace can simplify distribution and make cloud features available to users regardless of technical expertise.

In order to close this capability gap, we should design toward a world of many small clouds. We should encourage the proliferation of LibreOffice server components by designing them to be easy and inexpensive to host. Our client-server architecture should be designed to respect the limited computational and bandwidth resources of small cloud operators, and we should perform all expensive computations on the client side.

The desktop application should be designed with the assumption that users will adopt multiple cloud providers for different purposes, including on an ad hoc basis for one-time document collaboration.

Development Plan

Overview

Developing a web and cloud product is a major undertaking. In order to minimize project risk, this development plan is based around decomposing the project into multiple independent initiatives. Each initiative will have separate milestones and deliverables. We must complete all initiatives in order to have a competitive cloud strategy, but each initiative is an independent useful feature.

Responsive user interface

LibreOffice already offers multiple user interface styles. This initiative will expand on that prior work to offer a new optional user interface mode which is optimized for web and touch-based devices. The user interface should scale appropriately based on window dimensions, and should make uncommon actions possible, if not easy.
Specific user interface design and evaluation will be conducted as part of this initiative. This work should include closer studies of our major competitors.
Once the responsive user interface implementation is complete, it will be used as the default configuration for both the web and mobile distributions.

Web distribution using WebAssembly

We already have a working prototype of LibreOffice built for web browsers, which uses Qt and WebAssembly. This prototype is still in a rough state, but it demonstrates it is possible to create a version of LibreOffice for web which does not require large-scale duplication of effort or resource-intensive server components.

This initiative will build upon this WebAssembly prototype. Since the WebAssembly prototype already works, initial efforts in this area will mostly focus on polish and packaging, in order to create a minimally viable web-deployable version of LibreOffice.

Mobile distributions based on desktop version

This initiative will build upon ongoing research efforts to standardize on the Qt 6 VCL backend. The initial focus will be creating some minimally functioning builds of the desktop version of LibreOffice for Android and iOS emulators. Once working, these versions can be incrementally improved.

Document server and integration with desktop version

LibreOffice already supports a variety of remote file services. This initiative will build upon that prior work to introduce an easy-to-host LibreOffice first-party document server. This initiative will also include creating a more streamlined user experience for interacting with these servers.

This initiative will include research to identify best practices and any open standards we can adopt. The document server should be designed in a manner that can be easily extended or incorporated into other services.

Client-server collaborative editing

This initiative will study and incrementally implement client-server collaborative editing in the LibreOffice desktop version. For development purposes, we will initially use direct TCP/IP connections between LibreOffice instances. Eventually, the document server will be modified to coordinate collaboration and act as a proxy between clients.
There are outstanding proposals to develop peer-to-peer collaboration, in addition to adopting other distributed networking and file sharing technologies. That is an excellent vision for LibreOffice. However, that vision touches on many active research areas in computer science. At this time, it is not entirely clear how we should best approach executing on those proposals.

In order to reduce total project risk, this proposal suggests first implementing collaboration using a client-server network architecture, with a single authoritative state.
Support for client-server collaboration is not exclusive of peer-to-peer collaboration. The software changes we make to support client-server collaboration are also necessary for peer-to-peer collaboration. By making these changes separate of the hard peer-to-peer research problems, we will reduce the risk of a future peer-to-peer project and make it more attractive for development.

[1] Microsoft Office Online Server was discontinued in October 2025.

UPDATE: We have opened a discussion here: https://community.documentfoundation.org/t/web-and-mobile-development-strategy-proposal/13729

New Web and Mobile Strategy for LibreOffice

2026-05-272026-05-27

LibreOffice is a desktop application, and we will continue making it. But we have constant requests for web and mobile versions, so here is our updated plan. These are minutes from the TDF Team and Board of Directors meetings on web and mobile strategy for LibreOffice:

Who was present

Team: Michael Weghorn, Jonathan Clark, Sophie Gautier, Neil Roberts, Mike Saunders, Guilhem Moulin, Heiko Tietze, Ilmari Lauhakangas, Dan Williams, Xisco Fauli, Christian Lohmaier, Vissarion Fysikopoulos, Juan José Gonzalez, Olivier Hallot, Florian Effenberger, Hossein Nourikah

Board: Eliane Domingos, Mike Saunders, Paolo Vecchi, Simon Phipps, Sophie Gautier

Summary

The meetings, which took place April 20, April 22 and May 19, focused on discussing LibreOffice and TDF strategies for the evolving development landscape and the future of LibreOffice across all platforms – desktop, mobile, and cloud. Team roles were reviewed, and new assignments were proposed.

Status of the current foundation team activities

Since 2020, the development of LibreOffice within the foundation focused almost uniquely on the desktop version of LibreOffice (and to a lesser extent, the Android viewer app) and that part will continue unchanged. Therefore the foundation will continue to deliver two major LibreOffice releases per year.

Engineering Steering Committee (ESC)

The current ESC members and activities remain unchanged, and weekly meetings continue with reports on activities, releases, topics and project management. The meeting, as always, is open to the development community.

Community support

No changes in vision for community support. Regional events and special projects remains as they are, and require proper and timely project submission and available budget. Google Summer of Code and Outreachy will continue as before. The LibreOffice Conference 2026 is planned and will take place in Pordenone, northern Italy.

Marketing and communications

Marketing and communications will adapt to the current situation of the foundation and LibreOffice . More communication of team activities and product development is needed, as well as improving the use of social networks for mass communication. Unification of the several different blogs is under consideration.

Challenges ahead

The foundation is challenged to address the following areas:

Develop an online and mobile version of the suite. The challenge is to select the technology that fulfill both end-user and server side management
Innovate in collaboration such as peer-to-peer document editing
Continue to produce two releases per year of the desktop and Android viewer versions
Improve the user interface and usability of LibreOffice
Keep the quality and security of the office suite
Develop new features and improve current features
Cherry-pick relevant features and improvements from other software producers
Full support of the Open Document Format (ODF)
Produce adequate documentation for development processes and the current and new products
Be an active participant of the major open source communities and government initiatives for FOSS and nations’ sovereignty
Preserve donation inflow and pursue corporate or government donations through development projects

New assignments of the team

It was suggested that the team be distributed in two parts, with proper interaction between the groups. Additional headcounts, as well as external contracts are considered to fulfil the mission. New community developers will be assigned to tasks upon demand.

Of critical importance, the suite security and CVE’s management were assigned to Christian Lohmaier (Release engineer) and Xisco Fauli (Quality Control). Coverity and OSS-Fuzz services are assigned to Xisco Fauli. These new missions require additional manpower, and provisions for hiring an additional QA specialist is needed.

The team will select valuable technology and code under FOSS licenses, and from companies using LibreOffice Technology.

Mobile, cloud and peer-to-peer development

Mobile and cloud development management is assigned to Jonathan Clark (leader), with support from Dan Williams, Michael Weghorn and Neil Roberts. The planning and priority goals established are based on Jonathan Clark’s “Web and Mobile Development Strategy Proposal” for the remainder of 2026, and include:

WebAssembly (WASM) Optimization: Enhancing and polishing our functional prototype based on Qt 6 and WebAssembly. This technological route will run the application robustly and natively directly inside the user’s browser, without overloading hosting servers.
Accelerating the mobile project: The goal for 2026 involves technical advancement in the graphical user interface (GUI) code and testing builds on Android and iOS emulators, with advisory support from Dan Williams for iOS-specific topics.
Smart collaborative editing: We will initiate practical collaborative editing tests using a stable client-server architecture (via direct TCP/IP connections), paving the way before advancing to peer-to-peer (P2P) network research.

Conclusion

The Document Foundation is challenged to evolve and expand LibreOffice to other computing platforms, and include collaboration editing. This requires changes in the current team activities, mission and organization. The Board and the team are fully committed to addressing these challenges and reporting to the public the development and achievements obtained. Freedom has never been so valuable for the LibreOffice community.

Discuss our plan and strategy on our forum here

Projects selected for LibreOffice in the Google Summer of Code 2026

2026-05-09

The LibreOffice Google Summer of Code projects have been selected for 2026.

Aya Jamal – OpenType MATH: this project aims to add support for OpenType fonts that contain a MATH table. Data from the MATH table will be used to layout math formulas.
Manish Bera – Improve word processor test coverage: Writer is the most complex application in LibreOffice. The tests written in the scope of this project will make for a better developer experience. One aim is to restart the automated generation of LCOV test coverage reports.
Jesus Solis – JPEG XL import support: while JPEG XL has only recently started to be adopted by web browsers, it is already used in fields such as medical imaging, professional photography, PDF & EPUB authoring and handling geospatial and archival data. Having support for it in LibreOffice would therefore make for a smoother experience for the users who rely on the format.

Good luck to the contributors – we appreciate their work on these important features and improvements! And thanks to our mentors for assisting them: Khaled Hosny (Alif Type); Jonathan Clark and Xisco Faulí (TDF).

Between August 17 and 24, contributors will submit their code, project summaries, and final evaluations of their mentors. Find out more about the timeline here, and check out more details about the projects on this page.