I have been running my own business on Microsoft 365 for six years. I pay about $12 a month for the Business Basic tier, which gives me Word, Excel, Outlook, Teams, and OneDrive. I have been looking for an open-source alternative for about three of those years, and the closest I ever got was Nextcloud with Collabora, which worked for documents but not for the parts of my workflow that depend on Outlook calendar invitations. A new project called Euro-Office launched last week with the explicit goal of replacing Microsoft 365 for European small businesses, and I have been running it for seven days.
What Euro-Office actually is
Euro-Office is a bundle of open-source applications packaged together with a managed service on top. The bundle is built around LibreOffice (the open-source office suite, a free alternative to Microsoft Word, Excel, and PowerPoint) for documents, Thunderbird (the open-source email client maintained by Mozilla) for email, and a custom-built calendar and contacts server. The managed service adds single sign-on (logging in once to access all of the bundled apps), automatic backups, and a hosted instance option. You can self-host the whole thing, or you can pay a small monthly fee and let the project team host it for you.
The Euro-Office pitch is that the project is built by Europeans, hosted in European data centers, and governed by European data protection rules (the GDPR, the General Data Protection Regulation, an EU law that governs how companies collect and store personal data of EU residents). That matters if your customers are in the EU and you have to show that your data is not flowing to a US-headquartered vendor. The technology is mostly existing open-source projects, glued together with a custom authentication layer and a unified web interface.
The hosted version is $4.99 per user per month. The self-hosted version is free, but you have to run the deployment yourself. The deployment is a Docker Compose file (a configuration file that tells Docker, a popular containerization tool, which services to start and how they connect) plus a small amount of setup. The five applications are:
- LibreOffice Writer. Word processor, opens and saves .docx files cleanly.
- LibreOffice Calc. Spreadsheet, opens and saves .xlsx files. Same formulas, same chart types.
- LibreOffice Impress. Presentations, opens and saves .pptx files. I have not stress-tested this one.
- Thunderbird. Email client, supports IMAP and SMTP (the two standard protocols for reading and sending email), no built-in tracking or ads.
- Calendar and contacts server. Custom-built by the project team, speaks CalDAV and CardDAV (the standard protocols for syncing calendar events and contacts with a server) so third-party apps like the iOS Calendar app and the GNOME Calendar app can sync against it.
How the migration went
I migrated one of my email accounts first. The Euro-Office team provides a tool that imports mail from IMAP, and it took about three hours to move 18 months of email from my Microsoft-hosted account. The tool preserved folder structure, but it lost my read/unread status on about 10% of messages. That is annoying but not catastrophic. I can live with it.
The calendar was harder. The import tool does not support Outlook calendar exports, which is the format Microsoft 365 produces. I had to export my calendar as an .ics file (a standard calendar file format that most calendar apps can read), then re-import it. The .ics export from Outlook took about 10 minutes, and the import into Euro-Office took another 15 minutes. The events came across with the right titles and times, but about a third of them lost their reminder settings. I had to go through and re-add reminders for important client meetings.
The contacts imported cleanly. I exported from Outlook as a .csv file (a simple spreadsheet format), and the Euro-Office import tool handled it without complaint. About 5% of my contacts had odd characters in their names that did not survive the export-import round trip, but the data was still readable.
Documents are where the friction was lowest. I uploaded a few .docx files to the Euro-Office document server, opened them in Writer, made some edits, and saved them back as .docx. The round trip preserved formatting cleanly. One of my clients, who is on Microsoft 365, opened the saved file and reported no issues. This is the part of Euro-Office that I trust the most.
What I gave up
I gave up Outlook’s focused inbox. Outlook (the email client that comes with Microsoft 365) sorts incoming mail into “Focused” and “Other” tabs, and it learns over time which senders you care about. The Euro-Office email view is a single chronological list. I can filter and label, but I cannot replicate the focused-inbox behavior. I missed it within two days.
I gave up Teams. The Euro-Office bundle does not include a chat or video calling application. The project team is working on integrating Element (a chat app built on the open Matrix protocol, an open standard for real-time messaging) but as of this week, the integration is not in the main bundle. I have been using a separate Element install for team chat, which works but means I have two different logins and two different apps to switch between.
The deep Word-Excel integration is the third thing I gave up. In Microsoft 365, you can embed an Excel chart in a Word document, and the chart updates if the underlying spreadsheet changes. In Euro-Office, you can embed a chart, but it does not update. You have to manually re-embed the chart. For my workflow, this was a minor inconvenience. For an analyst who lives inside Word and Excel, it would be a deal-breaker.
Trade-offs
Euro-Office is not free in time. The migration took me about six hours total, spread across two days. Most of that time was on the calendar import. If you are a one-person shop, the migration is a weekend project. If you are migrating a team of 10, you should budget a full week.
Euro-Office is not free in polish. The web interface is functional, but it is not as smooth as Microsoft 365. The icons are a little smaller, the loading transitions are a little longer, and the menu structure in Writer is slightly different from the menu structure in Word. None of this is a deal-breaker, but you will feel the difference in the first week.
The feature gaps are the third cost. There is no equivalent of Power Automate (Microsoft’s tool for building automated workflows between apps), no equivalent of the Power BI dashboarding tools, and no equivalent of the deep SharePoint integration (SharePoint is Microsoft’s document management and intranet platform). If your business depends on any of those, Euro-Office is not ready for you.
In our case, I am going to keep using Euro-Office for my personal email and documents and keep paying for Microsoft 365 for my client-facing work. The reason is that some of my clients are on Microsoft 365, and the deep integration matters when we are sharing documents and scheduling meetings. Your math will be different if your customers are not tied to the Microsoft stack.
If you are a small business that uses Microsoft 365 for email, documents, and calendar, and you are paying $12 a month per user, Euro-Office at $4.99 per user per month will save you real money. If you are a larger organization with custom workflows, the migration cost will eat the savings for the first year.
Bottom line
If you only do one thing from this article, export your Microsoft 365 calendar as an .ics file and try opening it in LibreOffice. If the import works cleanly and your reminders survive, you have a real shot at migrating. If your reminders disappear and the time zones are wrong, the migration will take longer than you think.