Microsoft 365 Alternative from Europe
Email, calendars, files, office and video meetings with European open source software, operated in Germany. Also an alternative to Google Workspace.
Microsoft 365 and Google Workspace are standard in many companies. Both providers are headquartered in the US and are therefore subject to US law, even when data is stored in European data centers.
BARNICOM assembles a workplace from European open source software, sets it up and runs it. Your data stays on servers in Germany or in your own data center. You get one sign-in for all services and one point of contact for the entire operation.
Public administrations are taking the same route. In 2025, the German state of Schleswig-Holstein moved its email infrastructure with around 40,000 accounts from Exchange and Outlook to Open-Xchange and Thunderbird (heise online). The German federal administration relies on openDesk, a workplace built from the same components (German Bundestag).
Why companies look for alternatives
Access under US law
The US CLOUD Act of 2018 requires US providers to hand over data to US authorities on request, regardless of where it is stored. In June 2025, Microsoft France told the French Senate it could not rule out such a transfer (report).
Pricing and licensing
Prices, licensing models and features are set by the provider and can change unilaterally. With all data and processes in one place, there is little room to move.
Dependence on one vendor
Email, files, sign-in and meetings all depend on the same corporation. Outages, account suspensions or contract changes affect the entire workplace.
What replaces what
The functions of Microsoft 365 and Google Workspace and European open source solutions that cover them. Which combination fits your company is something we work out together.
| Area | Microsoft 365 | Google Workspace | European alternatives |
|---|---|---|---|
| Email, calendar, contacts | Exchange Online, Outlook | Gmail, Google Calendar | Open-Xchange, grommunio or mailcowGermany, Austria |
| Files and sharing | OneDrive, SharePoint | Google Drive | NextcloudGermany |
| Chat and video calls | Teams | Google Chat, Meet | Nextcloud Talk or Element (Matrix)Germany, United Kingdom |
| Office in the browser | Office for the web | Docs, Sheets, Slides | Nextcloud Office (Collabora Online)United Kingdom |
| Desktop office | Word, Excel, PowerPoint | no desktop version | LibreOfficeGermany |
| Users and sign-in | Entra ID | Cloud Identity | Univention Corporate ServerGermany |
| Backup | Microsoft 365 Backup or third party | third party | Proxmox Backup ServerAustria |
| Complete suite | Microsoft 365 | Google Workspace | openDesk with Open-Xchange, Nextcloud, Collabora and moreGermany |
| Operations | Microsoft data centers | Google data centers | Data centers in Germany or your own data centerGermany |
Origin refers to the vendor’s headquarters. All solutions listed are open source and can run in Germany or in your own data center.
How the switch works
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Assessment
Which services, mailboxes, shares and business applications are in use? The result is a plan with effort and timeline.
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Pilot
One team works with the new environment first, so open issues surface before everyone moves.
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Migration
Mailboxes, calendars and files move over, devices are reconnected. The switch happens on a fixed date.
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Operations
We take care of updates, monitoring, backup and support, with a service level agreement on request.
When the alternative is not a fit
Switching does not make sense in every case. We point out limitations beforehand, for example with:
- business software that requires add-ins for Word, Excel or Outlook, for example in tax advisory or accounting
- many Excel macros or complex Office templates
- processes tightly bound to Microsoft services such as Power Automate or Dynamics 365
Frequently asked questions
Can we keep using Outlook?
Depending on the solution chosen, Outlook can stay in use, with grommunio for example as usual with email, calendar and contacts. Thunderbird and browser webmail are available as well. We work out the right option together.
What is openDesk?
openDesk is a workplace built from open source components, developed on behalf of the German federal government by the Center for Digital Sovereignty (ZenDiS). It includes email with Open-Xchange, files with Nextcloud, office with Collabora and video meetings, among others. The federal administration already uses it, and openDesk is now also available to companies.
Can we switch step by step?
Yes. Often file storage moves first, followed by email and calendars. A small Microsoft account can remain for individual applications.
How long does the switch take?
It depends on the number of users, mailboxes and data volume. After the assessment you receive a timeline.
What does the alternative cost?
The software is open source, so there are no per-user license fees to Microsoft or Google. Costs arise for servers, optional vendor support contracts as well as setup and operations. You receive a proposal after the assessment.
Where is our data stored?
On servers in German data centers or in your own data center. You decide where the servers are located.
Can we still join Teams meetings from customers?
Yes. Teams meetings can be opened in the browser without a Microsoft license of your own.
Is open source secure enough for businesses?
The software we use is widespread in companies and public administration, and its source code is open to review. What matters most is operation with updates, monitoring and backup. We take care of that.
More alternatives for workplace and collaboration
Find out whether switching fits your company
We review your current environment and tell you what can be replaced and what cannot.