Y.js

Y.js provides CRDTs that make collaboration possible. These data structures automatically merge changes from multiple users without conflicts—the foundation for Google Docs-style real-time collaboration.

Key Features:

• CRDTs - Conflict-free data types that merge automatically
• Shared Types - Text, arrays, maps, and more
• Provider Agnostic - Works with any transport
• Offline Support - Changes sync when reconnected

Why Y.js:

• Conflict Free - No merge conflicts, ever
• Offline First - Works without constant connection
• Ecosystem - Rich text editors, integrations, providers
• Performance - Efficient sync with minimal data

Y.js data types:

• Y.Text - Collaborative rich text
• Y.Array - Collaborative lists
• Y.Map - Collaborative key-value
• Y.XmlFragment - Collaborative XML/HTML

Y.js is the technical foundation for serious collaborative applications. It's not a complete solution—you need transport and persistence—but it solves the hardest problem: making concurrent edits work.