XState is a production-grade TypeScript library for creating, interpreting, and executing finite state machines and statecharts, based on the SCXML standard and the actor model. The repository is a monorepo (pnpm workspaces) containing the core `xstate` package, the lighter `@xstate/store` for event-sourced state management, and framework-specific bindings for React, Vue, Svelte, Solid, Preact, and Angular. It also includes `xstate-inspect` for debugging, `xstate-immer` for Immer integration, a graph analysis module for model-based testing, and many example applications and templates. The core engine provides `createMachine`, `createActor`, `setup()` for type-safe machine definitions, built-in actions (assign, sendTo, raise, etc.), guard combinators, and actor logic factories (`fromPromise`, `fromCallback`, `fromObservable`). The store sub-package offers atoms, source atoms, and composable extensions like persist and undo/redo. The codebase demonstrates high craftsmanship with extensive TypeScript type inference, well-encapsulated modules, and comprehensive test coverage. It is actively maintained with continuous CI/CD and version management via changesets.
This is a monorepo for the Ember.js-based encrypted chat application 'emberclear', which provides end-to-end encrypted messaging with no server-side message storage. The architecture is modular, consisting of multiple Ember addons (crypto, networking, local-account, UI, test-helpers, tracked-local-storage) and a separate card game app (pinochle) that reuses the same networking and crypto infrastructure. The chat app uses public-key cryptography (tweetnacl, libsodium) via web workers, relays messages through Phoenix WebSocket relays, and persists data locally via IndexedDB and localStorage. It includes features like QR code identity sharing, channel voting with cryptographic chains, and a state-machine-driven setup wizard. The codebase is well-tested with QUnit, acceptance tests, and smoke tests, but shows signs of technical drift with outdated dependencies (Node 14, Ember 3.26.1), many TODO comments, and incomplete features (e.g., voting, QR login transfer). The pinochle game app appears experimental but demonstrates sophisticated state machine usage and animation systems.