AFFiNE is a cross-platform, block-based knowledge management application that combines notes, whiteboards, and databases in a local-first, real-time collaborative environment. Built on the BlockSuite editor framework, it features a modular architecture with extensible components, AI-powered capabilities (Copilot), and support for embedding external content. The application consists of a web client, desktop client (Electron), and mobile clients (iOS/Android), backed by a Node.js/NestJS server with Prisma ORM and Rust performance modules. Data is synchronized via Yjs CRDTs with a custom storage layer (nbstore) for offline-first capabilities.
TREK is a full-featured, self-hosted travel planning application built with NestJS (server) and React (client). It enables users to create trips, manage day-by-day itineraries, add places and reservations, track budgets, maintain packing lists, collaborate via real-time chat/notes/polls, and journal memories. The architecture is a monorepo with client, server, shared schemas, and a plugin SDK. Key capabilities include offline-first support via IndexedDB with a mutation queue, real-time WebSocket collaboration, MCP (Model Context Protocol) integration for AI tools, a plugin system with sandboxed RPC host, OAuth 2.1, OIDC SSO, passkeys, and a storage abstraction layer supporting local and S3 backends. The application is production-ready with extensive test coverage (Vitest, Playwright E2E, MSW mocks) and internationalization across 23 locales. The codebase demonstrates strong engineering practices: modular NestJS domains, Zod schema-first validation shared between client and server, idempotent mutation handling, and a well-designed plugin SDK with permission gating and digital signatures.
Fluid Framework is a production-grade TypeScript monorepo for building real-time collaborative applications. It provides a layered client runtime stack (container-loader, container-runtime, datastore) and a family of distributed data structures (DDS) including SharedTree, SharedMap, SharedString/Sequence, SharedMatrix, and SharedCounter. State synchronization is driven by operation logs and summaries, with versioned op formats and codec families that allow protocol evolution. The repo also includes server components (Routerlicious, Tinylicious, Gitrest, Historian) that provide ordering, storage, tenant management, and REST APIs, plus driver abstractions for Azure Fluid Relay, ODSP, local files, and replay scenarios. The architecture is a large pnpm monorepo organized into release groups: client, routerlicious, gitrest, historian, and build-tools. Application developers integrate through container runtime factories and data-object patterns; DDS packages encode changes as versioned ops and summaries; server lambdas order, persist, and broadcast ops; Gitrest/Historian provide Git-based snapshot storage. The repository also contains extensive example apps (React-based collaborative textareas, dice rollers, staging, table editors) and a devtools browser extension, but those are reference/demo surfaces rather than the core product. Although classified as an application/library, the repository has a research-heavy character: SharedTree's design involves deep schema, codec, and change-family work; there are multiple generations of tree DDS (modern, experimental, and legacy PropertyDDS); and there is extensive stochastic/fuzz testing, snapshot compatibility testing, and performance benchmarking. The codebase is highly active and professionally maintained, with recent commits, robust changeset/CI tooling, and strong API compatibility automation. However, it carries notable legacy baggage: deprecated common-utils packages, experimental DDS code, duplicated server helpers, hardcoded test ports, and several half-completed migrations. These are mostly isolated to legacy corners, making the overall drift manageable.
Logseq is a privacy-first, open-source knowledge management platform built as a monorepo containing an Electron desktop app, Capacitor-based mobile apps (iOS/Android), a web app, and a Node.js db-sync server. The codebase is predominantly ClojureScript (CLJS) with React/Rum for the UI, DataScript for the in-memory graph database, and SQLite (via better-sqlite3 and sqlite-wasm) for persistence. It uses shadow-cljs for CLJS compilation, webpack for JS bundling, and Tailwind CSS for styling. A separate OCaml-based CLI (logseq-cli) built with Melange provides graph inspection, sync, and CRUD operations against the same db-worker-node backend. The architecture separates concerns into deps/ subprojects (db, outliner, graph-parser, db-sync, common, publishing, shui) that are compiled as separate shadow-cljs targets and shared across Electron, browser, mobile, and CLI runtimes. The system has two graph types: file-based graphs (Markdown/Org) and DB graphs (SQLite-backed with DataScript in-memory querying). DB graphs enable real-time collaboration (RTC) via a Cloudflare Worker-based sync server (deps/db-sync) using WebSockets and D1 SQLite. The db-worker-node is a long-lived Node.js process that manages SQLite connections and sync state, communicating with the UI via a thread-api IPC mechanism. The outliner module handles block tree operations with structural invariants, while the graph-parser handles Markdown/Org parsing via mldoc. The publishing module generates static HTML sites from graphs. Key architectural patterns include: missionary for reactive async flows, promesa for promise composition, malli for schema validation, datascript for Datalog queries, and a component-based UI with Rum/React. The codebase has extensive test coverage via cljs.test, Playwright E2E tests (clj-e2e), and Python-based CLI E2E tests (cli-e2e). The repository is actively maintained with recent commits, 43k+ stars, and active issue triage, though the large monorepo complexity and multi-language surface (CLJS, OCaml, Swift, Kotlin, Python, JS) create maintenance challenges.
Hermes Studio is a self-hosted AI agent orchestration platform providing a unified interface for multiple AI agents (Hermes, Ekko, Claude Code, Codex, Pi) with chat, workflow automation, agent management, and skill-based extensibility. The architecture features a Vue 3 frontend, Node.js/Koa backend, Electron desktop client, and hybrid TypeScript/Python agent runtime. Key capabilities include real-time collaboration via Socket.IO, voice processing with multiple STT/TTS providers, file management with preview capabilities, usage analytics, and Model Context Protocol (MCP) integration for extending agent tools. The platform supports social messaging integrations (Feishu, Telegram, Weixin) and MCU device support for embedded voice processing.
This repository is a monorepo containing Blockly plugins and example applications that demonstrate how to extend and customize the Blockly visual programming library. It provides reusable UI components (custom fields, toolbox enhancements, workspace minimap), real-time collaboration features, and developer tools for creating custom blocks. The architecture follows a plugin pattern where each extension is self-contained with its own source, tests, and package.json. Examples showcase practical integrations like block factories, serialization, and multi-user editing. The codebase is actively maintained with regular updates to track Blockly releases and employs Lerna for workspace management.
ClawDeckX is a desktop/web application that provides a management interface for the OpenClaw AI gateway. It enables users to configure and manage AI agent collaborations, monitor system metrics, install extensions, and access a template marketplace for agent configurations. The application features a Go backend with REST API and WebSocket endpoints, a React/TypeScript frontend, and uses SQLite/PostgreSQL for data storage. Key capabilities include real-time agent room collaboration, configuration management, multi-agent workflow orchestration, notification systems, and cross-platform deployment options.
Plane is an open-source, self-hosted project management platform that provides issue tracking, sprint planning (cycles), modules, pages (wiki), views, analytics, and real-time collaborative editing. The repository is a monorepo containing a Django REST API backend with Celery workers, multiple React frontends (main web app, public space app, admin panel), and a Hocuspocus-based live collaboration server. The architecture follows a service-oriented pattern with shared packages for UI components, editor extensions, types, utilities, and state management via MobX. The codebase demonstrates strong engineering practices with a rich filter system, extensible permission model, and a clean exporter pattern, though it shows signs of ongoing migration from Next.js to React Router and some code duplication across apps.
OS1 (nokodo) is a full-stack AI-powered collaborative platform combining autonomous agents, deep research, real-time collaboration, and extensible tooling in a self-hostable workspace. The system features a modular architecture with FastAPI/Python backend, Svelte 5 frontend, and separate admin console, communicating via REST API, WebSocket, and Redis pub/sub. Core capabilities include AI agent construction with tool integration (web search, code execution, file operations), persistent memory system with vector search, real-time document editing, and comprehensive resource management (threads, notes, files, projects, calendars, reminders). The platform emphasizes extensibility through plugin systems for tools, filters, and hooks, with production-ready deployment via Docker Compose.
Macro is a large open-source monorepo (AGPLv3) for an all-in-one collaborative productivity platform that unifies email, messaging, documents, tasks, CRM, AI agents, and more. The backend consists of 42+ Rust microservices following a consistent hexagonal architecture (domain/inbound/outbound), with PostgreSQL, OpenSearch, Redis, S3, Kafka/SQS/EventBridge for data storage and event-driven processing. The frontend is a SolidJS single-page application with a heavily customized Lexical editor, block-based content system, real-time collaboration via CRDT (Loro), and Tauri-based desktop/iOS apps. AI is a first-class feature with agent harnesses, MCP integration, and an AI editing worker. Infrastructure is managed via Pulumi and Docker Compose for local development. The codebase demonstrates high engineering craftsmanship with consistent patterns, extensive testing, and comprehensive observability, though the sheer scale and volume of generated code introduce some maintenance overhead.
This is a monorepo for a web-based vector graphics editor (similar to Figma) built with React, Canvas2D, and TypeScript. It features a core editor with drawing tools, layers, path editing, undo/redo, SVG import/export, and real-time multiplayer collaboration (via Yjs/Hocuspocus). The architecture includes a standalone editor app, a deprecated multiplayer variant, a backend (NestJS + Prisma + PostgreSQL) for authentication and file storage, and a workbench for team management. Shared packages provide geometry utilities, UI components, icons, and Skia PathKit WASM bindings. The codebase demonstrates strong engineering patterns (command pattern, event emitter, strategy pattern) and provides several reusable components, especially the geometry library and UI components. However, there is significant code duplication between the standalone and multiplayer apps, and the multiplayer app is deprecated, indicating some drift risks. The backend is functional but has minimal stubs and a hardcoded JWT secret.
Pogly Standalone is a real-time collaborative overlay editor designed for streamers. It allows multiple users to jointly create and manage stream overlays (text, images, widgets) that can be displayed in streaming software like OBS. The application features a React frontend with TypeScript, utilizing Material-UI and styled-components for the UI, and a C# backend powered by SpacetimeDB for real-time state synchronization. Key functionalities include drag-and-drop interface, layout management, role-based permissions (owner/moderator/guest), integration with streaming platforms (Twitch, YouTube, Kick) and emote services (7TV, BetterTTV, Tenor), and persistent storage via Docker volumes. The architecture follows a modular structure with clear separation of concerns: the frontend handles user interactions and rendering, while the SpacetimeDB backend serves as the authoritative state store, pushing updates to all connected clients via WebSocket. Deployment is containerized using Docker with Caddy serving the frontend and proxying to SpacetimeDB.
BigBlueButton is an open-source web conferencing system designed for online learning. It provides real-time audio/video, screen sharing, whiteboard, chat, polling, breakout rooms, and recording/playback. The architecture is distributed and polyglot: a Scala/Akka backend handles meeting logic and state via Redis pub/sub; a Java API layer exposes REST endpoints for meeting creation and recording management; a React frontend with GraphQL subscriptions enables real-time collaboration; Ruby workers process recordings; and a Go GraphQL middleware optimizes subscription delivery. The system integrates with FreeSWITCH for legacy voice and LiveKit for modern WebRTC audio. A plugin SDK allows third-party extensions via customizable UI areas and data consumption hooks. Despite a large feature set and active development, the codebase suffers from significant technical debt due to its multi-language nature, incomplete migrations (e.g., from Meteor to pure React), duplicated logic across frontend and backend, and outdated library versions. Reusable components include the Redis pub/sub framework, GraphQL subscription deduplication hooks, and an annotation export service.