Best Open Source Alternatives to Microsoft 365

Compare the best free and open-source alternatives to Microsoft 365 — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated August 2026 · 7 alternatives

Microsoft 365

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Platformsweb, desktop, mobile, windows, macos, android, ios

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Microsoft 365 alternatives compared

Open-source alternatives to Microsoft 365, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Etherpad	18,465	Apache-2.0	LinuxmacOSWindowsDocker	Yes	Jul 2026	Visit
CryptPad	7,814	AGPL-3.0	LinuxmacOSWindowsDocker	Yes	Jul 2026	Visit
ONLYOFFICE Docs	6,772	AGPL-3.0	LinuxmacOSWindowsDocker	Yes	Jul 2026	Visit
LibreOffice	4,185	MPL-2.0	LinuxmacOSWindows	No	Aug 2026	Visit
Collabora Office	3,313	MPL-2.0	Linux	No	Jul 2026	Visit
Collabora Online	3,313	MPL-2.0	LinuxmacOSWindowsDocker	Yes	Jul 2026	Visit
Apache OpenOffice	1,223	Apache-2.0	LinuxmacOSWindows	No	Aug 2026	Visit