MiroTalk P2P is a self-hosted, open-source WebRTC video conferencing application that enables real-time peer-to-peer video calls, audio calls, screen sharing, chat, whiteboard collaboration, file sharing, and recording. The architecture consists of a Node.js/Express server with Socket.IO for signaling and a REST API (v1) for programmatic meeting management, token generation, and statistics. The client is a single-page application with modular JavaScript files handling UI components, media processing, accessibility, and integrations. Key features include end-to-end encrypted media (SRTP/DTLS), noise suppression via RNNoise AudioWorklet, live captions (Web Speech API and server-side Whisper transcription), ChatGPT integration, OIDC authentication, JWT-based API security, and an embeddable support widget. The system is designed for privacy: no persistent storage of signaling data, chat, or media; recordings stay in the browser as Blobs. Deployment options include Docker, Kubernetes, and bare-metal, with support for CoTURN TURN servers, ngrok tunneling, and email alerts via Nodemailer. The codebase is well-structured with separate modules for security (XSS sanitization, input validation, host protection), logging, and integration helpers, though the main server.js is monolithic (~2000 lines) and the client-side CSS is large (~5000 lines combined).
Linphone Desktop is a production-grade, cross-platform SIP softphone built on the Linphone C++ SDK and wrapped in a Qt6/QML user interface. It delivers audio/video calls, instant messaging (including group chat, file transfer, reactions, and ephemeral messages), conference scheduling, call recording, and presence management across Windows, macOS, and Linux. The architecture follows a strict MVVM split: model classes run on the Linphone SDK thread and expose Qt signals, while GUI-facing 'Core' classes live on the main thread and communicate with models via a custom SafeConnection template that enforces thread affinity. QML views bind directly to these cores, with list proxies (e.g., ListProxy, SortFilterProxy) providing paginated, filterable models for contact lists, call history, and chat logs. The codebase also integrates advanced features like OIDC/OAuth authentication, LDAP/CardDAV address book sync, end-to-end encryption (LIME/DTLS/SRTP), and system-level integrations (toast notifications, tray icons, screen-sharing, autostart) with per-platform backends. The repository is actively maintained with a modern build system (CMake), comprehensive GitLab CI pipelines (Linux, macOS, Windows, Squish GUI tests), and a substantial localization effort (multiple .ts files).
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.