Microsoft 365 bundles Office apps, Exchange email, OneDrive and Teams on a per-user subscription. Self-hosted groupware suites replace email, calendars, contacts, files and collaboration on your own servers, trading licence fees for infrastructure you manage.
8 open-source alternatives to Microsoft 365 you can host yourself, ranked by GitHub stars and updated daily.
| # | App | Category | Stars | Language | Updated |
|---|---|---|---|---|---|
| 1 |
nextcloud/server
|
File Sync & Sharing | 37,483 | PHP | today |
| 2 |
owncloud/core
|
File Sync & Sharing | 8,849 | PHP | 2d |
| 3 |
cryptpad/cryptpad
|
Office Suites | 8,071 | JavaScript | 1d |
| 4 |
sandstorm-io/sandstorm
|
Self-hosting Platforms & PaaS | 7,082 | JavaScript | 10d |
| 5 |
Alinto/sogo
|
Groupware | 2,186 | Objective-C | today |
| 6 |
EGroupware/egroupware
|
Groupware | 304 | PHP | today |
| 7 |
Intermesh/groupoffice
|
Groupware | 288 | PHP | 1d |
| 8 |
tine-groupware/tine
|
Groupware | 22 | HTML | today |