CryptPad

CryptPad provides an open-source, full-fledged office suite with all the tools necessary for productive collaboration.

Applications Include:

• Rich Text documents
• Spreadsheets
• Code/Markdown editor
• Kanban boards
• Slides/Presentations
• Whiteboard
• Polls

Key Features:

• Zero-knowledge encryption - even the server can’t read your documents
• Real-time collaboration with color-coded authors
• Chat, contacts, and comment systems
• Self-hosting option available
• Official instance at CryptPad.fr maintained by XWiki-SAS

Perfect for: Teams that need online collaboration with strong privacy guarantees.