Uppy is a modular, client-side JavaScript file upload library with a companion server (Companion) for remote provider integrations. It provides a plugin-based architecture where core functionality (file selection, upload strategies, UI components) is encapsulated in reusable packages. The client-side library supports drag-and-drop, webcam/screen capture, image editing, thumbnail generation, and multiple upload backends (tus resumable, AWS S3 multipart, XHR, Transloadit). The Companion server handles OAuth flows, remote file listing/download from providers like Google Drive, Dropbox, Box, OneDrive, Facebook, Zoom, Unsplash, and WebDAV, as well as S3 presigning and Transloadit Storage integration. The repository is a monorepo with over 50 packages, including framework-specific wrappers for React, Vue, Svelte, and Angular, plus headless controllers for custom UI. Key entry points are @uppy/core (Uppy class, plugin system), @uppy/dashboard (main UI), @uppy/companion (Express server), and @uppy/aws-s3 (S3 upload client). Data flows: user selects files via UI plugins, which are then uploaded via configured uploader plugins; remote sources are fetched through Companion using OAuth tokens. External dependencies include tus-js-client, AWS SDK, Transloadit API, and various OAuth providers. The codebase is well-tested with unit, integration, and browser tests, and uses modern TypeScript, ESM, and Preact for UI.
Servo is a parallel web browser engine written in Rust, designed to leverage modern hardware capabilities for rendering and script execution. The codebase is structured as a large Rust workspace with distinct components for scripting, layout, networking, styling, and media handling. The primary entry point is the 'servoshell' port, which acts as the browser host application. The repository includes extensive Web Platform Tests (WPT) to ensure standards compliance, alongside a custom Python-based build and test infrastructure ('mach'). While the core engine is tightly coupled, several tooling components and specific subsystems (like storage and bindings) exhibit reusable architectural patterns. The project demonstrates high engineering craftsmanship in memory safety and parallelism, utilizing Rust's ownership model to prevent data races in the rendering pipeline. However, the sheer scale of the test suite (Web Platform Tests) and the reliance on auto-generated test files introduce significant maintenance complexity. The codebase maintains its own forks of core libraries (e.g., 'stylo', 'servo_arc'), which creates a medium risk of technical drift if upstream changes are not synchronized. The build system and test infrastructure are robust but complex, requiring specific tooling to reproduce builds across platforms.
Floorp is a Firefox-based browser that extends Gecko with a comprehensive feature layer including workspaces, split-view tiling, panel sidebar, PWA/SSB management, mouse gestures, keyboard shortcuts, command palette, tab stacks, design theming, private containers, external browser integration, notes, profile manager, and more. The architecture is hybrid: chrome components are built with SolidJS and injected via a custom loader into Firefox's XUL, while settings, new tab, notes, welcome wizard, and profile manager pages are standalone React/Vite web applications served within the browser. Configuration is stored in Firefox preferences with io-ts runtime validation, and cross-process communication uses a birpc bridge. The build system is Deno-based, orchestrating Vite builds, Firefox runtime patching, and platform-specific packaging (macOS App Shim in C++, Windows Tauri stub installer). The codebase demonstrates strong engineering practices with extensive test coverage (colocated browser tests, unit tests, integration tests), clean reactive state management patterns, and well-structured feature modules. However, it carries technical debt from multiple legacy migration paths, duplicated UI components across page apps, and tight coupling to Firefox internal APIs that require version-specific workarounds.