A self-hosted alternative to Google Workspace with custom-domain email, calendar, file drive, booking pages and AI agents, running on Cloudflare or Docker.
5.7K+172 this week885TypeScriptAGPL-3.0Well maintainedUpdated yesterday
2 alternatives
2 best open-source alternatives to Microsoft 365 (2026)
Looking for a free, open-source alternative to Microsoft 365? These 2 projects can replace it. Each one passed our quality screening and is explained in plain words, so you can compare stars, license and maintenance at a glance.
Quick comparison
| Project | Stars | License | Last commit |
|---|---|---|---|
| hieunc229/mailflare | ★ 5.7K | AGPL-3.0 | yesterday |
| modoboa/modoboa | ★ 3.5K | ISC | yesterday |
Mail hosting and management platform with a modern web UI, admin panel and webmail, built on Postfix and Dovecot.
3.5K490PythonISCWell maintainedUpdated yesterday
FAQ
- Is there a free, open-source alternative to Microsoft 365?
- Yes. The most popular open-source alternatives to Microsoft 365 on Repolode are mailflare, modoboa.
- Which Microsoft 365 alternative should I choose?
- mailflare has the most GitHub stars and is released under AGPL-3.0. Compare the license and last commit of each option in the table above before choosing.
How this list is made: AI reads each project's documentation to match it with products it can replace, every project passes our quality screening, and the list is ranked by GitHub stars. Stars updated Nov 6, 2026. How Repolode works