Open-source alternatives to Loro

BlockSuite is a collaborative block editor framework built on a hierarchical block tree data model with CRDT-based state synchronization for real-time multi-user editing. It provides an extensible block component system, allowing developers to define custom block types through declarative schemas, services, and rendering components. The editor is packaged as cross-framework web components, making it embeddable in any JavaScript environment. The framework distinguishes itself with a command-driven editing pipeline that composes type-safe editing actions with dynamic context sharing and control

Liveblocks is a realtime collaboration infrastructure platform that synchronizes application state, documents, and user presence across multiple participants using conflict-free replicated data types. It provides a managed backend for collaborative text editors, threaded commenting and annotation systems, in-app notifications, and AI copilot deployment, all built on a WebSocket transport layer with server-side room management APIs. The platform distinguishes itself through a headless component primitive system that exposes unstyled React hooks and composable building blocks, allowing develope

This project is a reactive, offline-first NoSQL database engine designed for JavaScript applications. It provides a robust framework for managing application state by synchronizing data across browsers, mobile devices, and server-side runtimes. By treating local storage as the primary source of truth, it enables applications to remain functional without network connectivity, automatically reconciling changes with remote backends once a connection is restored. The database distinguishes itself through a modular architecture that supports cross-environment synchronization and high-performance d

xi-editor is a high-performance text editor core written in Rust. It employs a client-server architecture that separates the backend editor logic from the user interface, allowing diverse frontends to communicate with the core via a standardized protocol. The project is distinguished by its use of rope-based text buffers for efficient manipulation of large documents and a collaborative engine powered by conflict-free replicated data types to synchronize concurrent edits. It further features an extensible plugin system that integrates external binaries and third-party tools through JSON-based

OrbitDB is a decentralized data storage system that enables the creation of serverless databases residing across a network of peers. It functions as a peer-to-peer database that integrates with a content-addressed storage layer to distribute and replicate data without a central server. The system utilizes conflict-free replicated data types to ensure eventual consistency and state convergence across distributed nodes. It maintains an immutable record of updates using a directed acyclic graph to preserve causal ordering and cryptographic integrity. Access is managed through a decentralized ide

ShareJS is a collaborative document database and synchronization engine designed for real-time shared state management. It provides an operational transform sync engine to enable simultaneous editing of plain-text and JSON data, and a RESTful synchronization API for managing document states via HTTP. The system features an offline-first data sync layer that queues local modifications while disconnected and automatically pushes edits upon reconnection. It also includes a middleware access control layer that intercepts database requests to enforce security policies and perform request rewriting

json-joy is a comprehensive library for building real-time collaborative applications and distributed systems. It provides a robust framework for managing shared JSON-like data structures that automatically merge concurrent edits from multiple users, ensuring consistent state across all replicas without requiring a central coordination server. The project distinguishes itself through a high-performance approach to data handling, utilizing conflict-free replicated data types and logical clock-based synchronization to maintain data integrity. It includes a specialized engine for navigating and

FluidFramework is a real-time collaboration framework and distributed state synchronization engine. It provides a collaborative data model library and a cloud-synced document system designed to replicate data structures across connected clients using ordered operations to ensure eventual consistency. The framework utilizes a client-server relay architecture to route and persist operations without requiring custom server-side business logic. It manages the lifecycle of collaborative sessions through shared data containers and implements conflict resolution strategies, such as last-writer-wins,

Hocuspocus is a backend framework designed to facilitate real-time collaborative editing and state synchronization in web applications. It functions as a server-side infrastructure that manages persistent WebSocket connections, enabling multiple users to edit shared documents simultaneously while maintaining data consistency through a conflict-free replicated data type engine. The platform distinguishes itself through a modular, middleware-driven architecture that allows developers to intercept document lifecycle events, enforce custom access control policies, and integrate external services.

cr-sqlite is a multi-master database replication system that uses conflict-free replicated data types to ensure eventual consistency across distributed nodes. It provides the core capabilities for offline-first data synchronization, allowing multiple database instances to merge concurrent updates and reach a consistent state. The project distinguishes itself through a combination of CRDT-based data replication and a WASM-based database engine, enabling full SQL execution and state persistence within web browsers. It supports peer-to-peer replication and cross-tab synchronization, utilizing ca

PartyKit is a serverless WebSocket backend platform for building real-time multiplayer applications. It provides a globally distributed edge computing runtime that runs stateful server code close to users, with automatic scaling and hibernation for idle rooms. The platform handles WebSocket connections, HTTP requests, and durable storage without requiring infrastructure management, and includes a client and server SDK with hooks, storage, and Yjs integration for building collaborative features. The platform distinguishes itself through per-room isolation using Durable Objects, where each uniq

Livestore is a reactive state management framework that utilizes a local SQLite database to store and synchronize application data. It provides an event-sourced state store that processes typed events through materializer functions to derive and persist application state. The framework implements offline-first data synchronization using a push-pull engine and append-only event logs to maintain consistency between clients and servers. It includes a real-time presence system for tracking user activity and shared session status across connected clients. The system covers a broad capability surf

Tiptap is a headless, modular framework designed for building custom rich-text editors. It provides a developer-focused abstraction layer over a structured document model, allowing for full control over the underlying schema through a plugin-based architecture. By separating document state management from the user interface, it enables the creation of tailored editing experiences that remain framework-agnostic. The project distinguishes itself through a robust collaborative engine that supports real-time multi-user editing, conflict resolution, and presence tracking. It integrates artificial

Xray is a collaborative text editor and distributed workspace manager that utilizes conflict-free replicated data types to synchronize real-time edits and directory structures across peers. It functions as both an Electron-based desktop application and a headless editor server that manages workspaces and file systems remotely for connected clients. The project distinguishes itself by integrating fine-grained version control tracking, recording keystroke-level changes and uncommitted edits between Git commits. It employs a decentralized synchronization model for working copies and uses operati

This project provides educational materials and courseware focused on the theoretical and practical foundations of distributed systems design. It serves as a comprehensive curriculum covering the disciplines of consensus, data consistency, reliability engineering, and scalability. The instructional content focuses on achieving cluster agreement through consensus algorithms and managing system-wide state via coordination frameworks. It includes a dedicated guide to data theory, exploring replication strategies, consistency models, and data convergence. The courseware covers a broad capability

Iroh is a peer-to-peer networking stack and distributed system designed for secure direct connections, content-addressed storage, and synchronized data sharing. It provides a foundation for decentralized applications by combining a QUIC-based networking layer with primitives for distributed state and data transfer. The project distinguishes itself through a comprehensive suite of decentralized capabilities, including a distributed data store using conflict-free replicated data types for collaborative synchronization and a content-addressed storage system for verifiable, resumable transfers of

Gun is a decentralized graph database and synchronization engine designed for real-time, peer-to-peer data management. It functions as a JavaScript library that enables applications to maintain consistent state across distributed nodes without relying on a central server. By utilizing conflict-free replicated data types and a gossip protocol, the system ensures that data updates propagate across the network and reconcile automatically. The project distinguishes itself through a focus on decentralized identity and security, utilizing public-key infrastructure to authenticate users and sign dat

Derby is an isomorphic MVC framework and real-time data synchronization engine designed for building collaborative applications. It functions as a bi-directional data binding library and template engine that shares a single codebase between Node.js and the browser to synchronize state across clients and servers. The framework distinguishes itself through the use of operational transformation to resolve data conflicts automatically, enabling real-time shared editing and multi-user collaboration. It employs a differential state mutation model to minimize updates by performing deep equality chec

DesktopEditors is an office suite application designed for creating and editing text documents, spreadsheets, and presentations across different operating systems. It serves as an OOXML compatible editor, ensuring that files are read and written according to Office Open XML standards for cross-platform document exchange. The suite functions as a collaborative document platform featuring real-time co-authoring, version tracking, and integrated communication tools. It also acts as an AI-powered document assistant and PDF editor, providing capabilities for content generation, automated spreadshe

Dat is a peer-to-peer file synchronization tool that combines an append-only, hash-addressed log with Merkle tree verification, cryptographic access keys, live streaming replication, and swarm networking for sparse, versioned file sharing. It stores file data and metadata in a cryptographically signed, versioned append-only log where each entry is identified by its hash, and uses public-key cryptography to secure archives with separate read and write keys. The tool enables live streaming replication of data between peers as entries are appended, with Merkle tree integrity verification that su

This project is a framework for building real-time collaborative rich-text editing environments. It provides a structured, schema-based engine that enforces document integrity while allowing multiple users to modify content simultaneously through synchronized state management and conflict resolution protocols. The editor distinguishes itself through a highly modular plugin architecture that supports the integration of complex, interactive UI components built with external frontend libraries. By utilizing a custom rendering engine and a versioned, immutable document state tree, it enables deve

This project provides a collection of conflict-free replicated data types implemented in Rust, designed to enable deterministic state synchronization across distributed systems. It functions as a framework for maintaining data consistency in decentralized environments where central coordination is absent. The library facilitates distributed state synchronization by tracking causal context and unique actor identifiers for every participant. This approach allows the system to resolve concurrent modifications through mathematical lattice structures, ensuring that all replicas converge to the sam

Firepad is a Firebase collaborative text editor and rich text editor component. It functions as a real-time collaborative framework and operational transformation engine designed to synchronize document editing across multiple concurrent users. The project provides tools for shared document synchronization and collaborative presence tracking, allowing users to see live cursor positions and identifiers. It supports rich text authoring integration for both formatted content and code editing. The system manages document consistency through shared document synchronization and provides capabiliti

Yoopta-Editor is a headless framework for building customizable block-based rich text editors. It utilizes a JSON-based document engine to manage editor state and provides a WYSIWYG interface for creating structured documents. The system separates core document logic from the visual layer, allowing for complete customization of the user interface. The framework is designed for real-time collaborative editing, featuring a synchronization engine with conflict resolution and remote cursor presence tracking. It offers a highly extensible plugin system that allows developers to define new content

Jazz is a local-first relational database and synchronization framework designed for offline-capable applications. It functions as a reactive state management system that treats database records as the primary source of truth, automatically updating user interfaces in real time as underlying data changes. The project distinguishes itself through a collaborative data synchronization model that utilizes row-level versioning to track branching edit histories. It implements a security engine based on identity-claim row security, which enforces granular permissions on individual records, and suppo

This project is a self-hosted documentation platform designed for collaborative knowledge base management. It provides a block-based editor that structures content as a tree of independent nodes, allowing for flexible layout composition and the creation of complex, nested document hierarchies. The platform distinguishes itself through an offline-first architecture that utilizes conflict-free replicated data types to maintain synchronization across multiple clients. This ensures that teams can continue editing content during network disconnections, with all changes merging automatically once c

Instant is a real-time backend as a service and relational graph database designed to synchronize data across clients automatically. It functions as a data synchronization layer that provides authentication, permissions, and relational data storage for web and mobile applications. The platform includes an optimistic UI framework that updates local interfaces immediately during writes and handles automatic server rollbacks. It also features a real-time presence system to broadcast transient user states, such as cursor positions and online status, to other connected clients. The system manages