Instead of Microsoft 365
Word, Excel, Outlook, Teams and OneDrive in one subscription.
You can replace every piece. Replacing all of them at once, for a business, is a migration project with a budget.
You lose: The file formats everybody else sends you, and one bill instead of six services.
Start here
Nextcloud
Files, calendar, contacts and office editing in one place. Each piece is a little rougher than Microsoft's.
github.com/nextcloud/servernextcloud.com
A database, object storage or mail config, plus backups.
Also worth a look
- ONLYOFFICE
Best compatibility with .docx and .xlsx. The editor is the product; storage is yours to add.
github.com/ONLYOFFICE/DocumentServerwww.onlyoffice.com/see-it-in-action
- Stalwart
Mail, calendar and contacts. Not the office suite.
What the desk has written
Facts checked 8 November 2026. Licences, activity and archive status come from each project's own repository; the verdict and the cost lines are the desk's.