Nextcloud is an open-source content collaboration platform providing file sync & share, groupware (calendar, contacts, mail), real-time office editing, chat and video conferencing.
36.6k stars5.1k forksAGPL-3.0last commit Actively maintained
15 self-hosted Microsoft 365 (Office) alternatives
Cloud subscription suite providing hosted Microsoft Office apps (Word, Excel, PowerPoint, Outlook) and related services including Exchange Online, OneDrive, SharePoint, and Teams for document editing, email, file storage, collaboration, and team communication.
Alternatives to Microsoft 365 (Office)
Production-ready mail server stack in a Docker container with SMTP, IMAP/POP3, LDAP auth, anti-spam/AV, DKIM/DMARC, and optional OAuth2 support.
18.8k stars2k forksMITlast commit Actively maintained
#3
Etherpad is a web-based real-time collaborative editor with chat, rich-text formatting, and a plugin framework for customization and integrations.
18.5k stars3k forksApache-2.0last commit Actively maintained
#4
CryptPad is an end-to-end encrypted collaboration suite with real-time editors, file storage, and sharing, designed to keep document contents private from servers and admins.
7.9k stars840 forksAGPL-3.0last commit Actively maintained
Self-hostable online office suite for viewing and collaboratively editing documents, spreadsheets, presentations, PDFs, and forms with strong OOXML compatibility.
6.9k stars1.3k forksAGPL-3.0last commit Actively maintained
Go-based, modular mail server implementing SMTP/LMTP/IMAP with built-in DKIM/SPF/DMARC, storage backends (SQLite/Postgres/S3), Prometheus metrics and Docker support.
6.1k stars326 forksGPL-3.0last commit Actively maintained
#7
Open-source Debian-based OS and control panel that simplifies installing, managing and securing web apps, mail and services via a web admin and app catalog.
3k stars351 forksAGPL-3.0last commit Actively maintained
Self-hosted collaborative office suite for Nextcloud providing real-time editing, high-fidelity rendering and support for DOCX, XLSX, PPTX and ODF formats.
452 stars146 forkslast commit Actively maintained
Stackspin is an open source platform that bundles common team collaboration apps with single sign-on, centralized user management, backups, and monitoring for admins.
Activity unknown
#10
Schleuder is an OpenPGP-enabled mailing list manager that encrypts list mail and supports remailing, allowing subscribers and non-subscribers to exchange secure emails via the list.
Activity unknown
Self-hosted enterprise collaboration suite providing email, webmail, calendaring, contacts, and administration for organizations.
Activity unknown
Collabora Online Development Edition (CODE) provides a self-hosted LibreOffice-based online editor for documents, spreadsheets and presentations for testing or small teams.
Activity unknown
#13
GNU Mailman is a mailing list manager for email discussion lists and newsletters, with web-based administration, archives, moderation tools, and bounce handling.
Activity unknown
#14
WikiSuite is an integrated open source suite combining wiki/groupware, chat and conferencing, webmail, search, and infrastructure management for organizations.
Activity unknown
#15
Citadel is an open source groupware and messaging server providing email, calendars, contacts, and a web interface with room-based collaboration.
Activity unknown
What replacing Microsoft 365 (Office) actually involves
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 8 of 15 shipped a commit in the last six months. Licences in this list: AGPL-3.0, MIT, Apache-2.0, GPL-3.0. In exchange you take on hosting, backups and updates yourself.
Browse everything in Collaborative Office Suites.
