ONLYOFFICE offers the closest thing to Microsoft Office compatibility among open-source suites, handling .docx, .xlsx and .pptx with high fidelity. You can self-host the free Community Edition for full control, or lean on its cloud and DocSpace services. The code is open source under the AGPL and published by Ascensio System in Latvia. Collaborative editing happens server-side so self-hosting is the private route, though the desktop editors also add encrypted Private Rooms. Choose it if Microsoft format fidelity and real-time co-editing are your priority.
ONLYOFFICE
Self-hostable suite with the best Microsoft format compatibility.
onlyoffice.com
FreemiumOpen SourceWindowsmacOSLinuxAndroidiOSWebLatvia
Pricing The self-hosted Community Edition is free; paid options include Docs Cloud from about $8/user per month and a one-time Enterprise home license around $149.
Strengths
- Excellent Microsoft Office format compatibility
- Self-hostable Community Edition under the AGPL
- Desktop, mobile and web editors
- Real-time collaboration built in
Considerations
- Cloud editing is server-side, not zero-knowledge
- Fuller features push toward paid tiers
Listed in Office Tools
