Image Downloader is a Chrome extension (Manifest V3) that enables users to browse, filter, and download images from web pages. The extension features a popup UI, side panel, and options page for configuring download behavior. It uses Preact with Signals for state management, Tailwind CSS for styling, and includes sophisticated image processing capabilities like deduplication, resolution-based filtering, and format detection. The architecture consists of a background service worker handling downloads, content scripts for image discovery, and multiple UI interfaces (popup, side panel, options). Key strengths include well-isolated reusable components for image deduplication and discovery, comprehensive test coverage, and modern build tooling with Bun.
FoxyProxy is a cross-browser extension (Chrome, Firefox, Edge) for advanced proxy management. It allows users to configure individual proxies, use pattern-based proxying (wildcard, regex, match patterns), set proxy per tab or container (Firefox), enable global exclude lists, and manage WebRTC settings. The codebase is highly modular, using ES modules and Manifest V3. It implements single proxy, PAC, and 'proxy by patterns' modes, with features like sync, import/export, a live log, pattern tester, and enterprise policy support. The architecture separates concerns clearly: background service worker handles proxy configuration via browser APIs, options page provides full UX, popup offers quick controls, and context menus add convenience. The code is well-structured, uses modern JavaScript (ES2022), and shows solid engineering practices. Reusable modules include pattern validation, file I/O, and flag display utilities.
Vimium is an open-source browser extension for Chrome and Firefox that brings Vim-style keyboard navigation to the web. The codebase implements a sophisticated mode system (Normal, Insert, Find, Visual, etc.) with a central HandlerStack for event interception and bubbling. It provides link hints, a Vomnibar for URL/bookmark/tab search with autocomplete, scrolling, marks, and tab management. The architecture is split into background scripts (service worker) and content scripts injected into every page, communicating via message passing. The extension uses a custom key-mapping DSL parsed by the Commands module, and stores settings in chrome.storage. The UI (options page, help dialog, HUD, Vomnibar) is rendered in iframes with secure messaging via MessageChannel. The codebase is mature, well-tested (unit and DOM tests), and actively maintained by a community of contributors. While primarily an application, it includes a curated list of top-level domains (resources/tlds.txt) for URL parsing, but no research or data pipelines.
ScriptCat is a sophisticated browser extension for managing userscripts with advanced AI agent capabilities. It features a multi-context architecture (content scripts, service worker, offscreen documents, popup/options UI) built with React, TypeScript, and modern web extension APIs. The extension provides userscript installation, execution, synchronization, network rule management, and an integrated AI chat interface with tool execution capabilities. Its architecture demonstrates strong separation of concerns and implements several reusable patterns for cross-context communication, storage abstraction, and caching.