Best Open Source Microsoft 365 Alternatives

Open-source collaboration suite offering encrypted document editing, file sharing, and team workspaces with complete privacy protection.

Tuta offers encrypted email, calendar and contacts with quantum-resistant security, protecting your privacy without ads or tracking.

Open-source online editor for documents, spreadsheets, presentations, and PDFs. Features real-time collaboration, AI integration, and accessibility tools.

A document management platform that helps you archive, organize, and search files with email ingestion, tagging capabilities, and powerful search functionality.

Complete free office suite compatible with Microsoft formats (.doc, .docx, .xls, .xlsx, .ppt, .pptx). Open source alternative with regular updates.

Powerful online document editor with Microsoft Office compatibility. Integrate into your infrastructure or use trusted hosting partners for secure team collaboration.