Choosing an online office: Euro-Office, ONLYOFFICE and Collabora

Module 6: Files and documents · Reading time: 11 minutes

Learning objective: After this lesson you can compare the online office suites you come across with European clouds, explain where they come from and how they differ, and use a short test to make a choice that suits your documents.

Key concepts: online office, document server, browser editor, collaborative editing, fork, AGPL licence, Euro-Office, ONLYOFFICE, Collabora Online, LibreOffice, openDesk, OOXML-native and ODF-native, desktop program, per-user licence

What is an online office?

With Google and Microsoft, the office suite is built into the service: you open a document in the browser and type. With a European cloud such as Nextcloud, that's usually a separate component: an online office, also called a document server. The cloud stores the file; the online office displays it in your browser, lets you edit it, and then writes it back. As a user you barely notice this: you click a document and it opens.

For your choice, it does matter. Each online office has its own foundation, its own strengths and its own history. In the European cloud landscape you mainly come across three, plus one workplace package that includes one of the three.

The three packages in brief

A fork is a split off: someone takes the public source code of an open source project and develops it independently further. That's allowed with open source, within the rules of the licence.

Euro-Office

Euro-Office was announced in March 2026 as a European alternative to Microsoft Office. The makers gave two reasons for splitting off from ONLYOFFICE: they considered the code a good foundation for Microsoft formats, and they wanted a project developed and governed in Europe, because, according to them, a large part of the ONLYOFFICE developers still work in Russia. The first stable version arrived on 9 June 2026. Euro-Office is not a standalone service: it's meant to be embedded in other platforms, such as Nextcloud, and is also available as a desktop program.

ONLYOFFICE

ONLYOFFICE is the original. It's known for its good rendering of docx, xlsx and pptx and a toolbar that resembles Microsoft Office. It's used in many clouds, including Nextcloud. There's a free community edition and there are paid editions with support.

Collabora Online

Collabora Online is the online version of LibreOffice, the well-known open source office suite. Collabora is one of the biggest contributors to LibreOffice. It works internally with ODF and opens docx, xlsx and pptx by converting them. For years it was the default package in Nextcloud (under the name Nextcloud Office) and it's also part of openDesk, the workplace package commissioned by the German government and developed by the Zentrum für Digitale Souveränität (ZenDiS). openDesk bundles, among other things, Nextcloud, Collabora, Open-Xchange (mail and calendar), Element (chat) and Jitsi (video calling).

The discussion around Euro-Office

A fair course should mention that Euro-Office didn't start without controversy. Briefly, the positions, without judgement:

• ONLYOFFICE believes the fork violates the licence, because Euro-Office removed ONLYOFFICE's logos and attributions from the code, and ended its cooperation with Nextcloud.
• The Euro-Office partners believe that those extra conditions about logos aren't valid under the AGPL licence.
• Critics pointed out in 2026 that a large part of the code still comes from the original developers, that Euro-Office keeps adopting changes from ONLYOFFICE, and that the project is hosted on GitHub, which belongs to Microsoft.

What does that mean for you? Mainly that "European" is a question with layers when it comes to software: who builds it, who decides about it, where does it run, who holds the keys? Lesson 2.1 gave you the five questions for this. For most small organisations, what weighs most heavily is where the service runs and who manages it, and whether the documents work well. With open source, you can also always switch: your files remain ordinary docx or odt files.

What should you base your choice on?

Don't choose based on name, but on your own documents and way of working.

1. Which format do you use? If you mainly work with docx and xlsx and with people who have Microsoft Office, Euro-Office or ONLYOFFICE usually fit best, because nothing gets converted. If you work with ODF, or a government client requires it, Collabora Online is strong.
2. Collaborative editing. All three let multiple people work in one document at the same time, with comments and tracked changes. Test it with two people.
3. Browser or program? Anyone who often works without internet, or wants a large screen with multiple windows, wants a desktop program that works together with the cloud.
4. What does your provider offer? Often you don't choose yourself: the provider offers one package, or lets you choose. Ask which one, who keeps it updated, and whether a licence is needed per user.
5. Your test set. The real decision is made when testing your own documents (lesson 6.5).

Bakkerij De Korrel did it like this: ten documents (a quote, a schedule, a price list, recipes, a presentation for a trade fair) opened in a test environment, edited, changed at the same time with a colleague, and sent back to the accountant. Because the accountant uses Excel and the bakery had used docx for years, it stuck with an OOXML package.

Browser or program on your computer

Start in the browser; it works on any computer and there's nothing to install.

In practice: what it looks like with a provider

WebOké first used Collabora in Nextcloud (under the name Nextcloud Office) and is switching to Euro-Office in 2026. If you have an Office licence, you open a docx with one click in the browser; in the top right you see, via the button with little figures, who's working on it with you. The desktop program is, confusingly, also called Nextcloud Office, but that's Euro-Office for Windows, Mac (Apple Silicon) and Linux. Other providers offer ONLYOFFICE, Collabora or Euro-Office, sometimes letting you choose. You can ask the questions from this lesson with any provider.

Summary

• An online office is a separate component that lets you edit documents from your cloud in the browser.
• Euro-Office (fork of ONLYOFFICE, 2026) and ONLYOFFICE work internally with docx, xlsx and pptx; Collabora Online (LibreOffice) with ODF.
• There's a licence and origin discussion around Euro-Office; "European" is a question with layers.
• Choose based on your formats, collaboration, browser or program, and what your provider offers.
• The real test is trying it with your own documents.

Quiz

Exercise

Exercise E6.4: Trying out an online office. Open three of your own documents (a text document, a spreadsheet and a presentation) in the online office of a European provider (for example, in a trial account). Edit one of them at the same time as a colleague, add a comment, and download the result in the format used by your collaboration partner. Answer the questions about what went well and what didn't.

Further reading

The steps in these articles apply to WebOké's services; with other providers it works in a similar way.

• Euro-Office guide 1.1: What is Euro-Office?
• Euro-Office guide 1.3: Euro-Office or the old Nextcloud Office: what changes for you?
• Euro-Office guide 8.1: Working on a document at the same time
• Euro-Office guide 10.1: Euro-Office as a program on your computer: what is it and when do you use it?
• Euro-Office guide 13.2: The switch to Euro-Office
• Nextcloud, blog "Euro-Office: General availability set for June 9" (nextcloud.com/blog)
• Collabora Online (collaboraonline.com), ONLYOFFICE (onlyoffice.com), openDesk (opendesk.eu)