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.
Shower is an HTML presentation engine built as a monorepo containing a core library, two CSS-only themes (Ribbon and Material), a CLI tool, and a starter template. The core engine, written in vanilla JavaScript, handles slide management, keyboard and touch navigation, inner slide steps, progress bar, timer, full-screen support, and accessibility. The CLI provides commands for creating, serving, bundling, archiving, and publishing presentations, as well as PDF export via a self-downloading Chrome engine. Themes use advanced CSS features like custom properties and the tan(atan2()) scaling trick, and are entirely decoupled from the engine. The repository is well-tested with Playwright and GitHub Actions CI, uses modern Node.js (ESM, workspaces), and demonstrates clean architecture with lazy-loaded CLI commands and a plugin-based core.
Vimium C is a browser extension that provides keyboard-driven navigation and productivity features, forked from Vimium. Its architecture is a classic Chrome/Firefox extension with a background service worker or page, content scripts injected into every page, and extension pages (options, omnibar, show image). The background script manages state, settings, browsing data (history, bookmarks), and orchestrates commands like tab management, URL opening, and synchronization. Content scripts implement the core user-facing features: link hints (detecting clickable elements and overlaying markers), keyboard key handlers with a finite state machine for mapping keystrokes to commands, visual mode for text selection, find-in-page, scrolling with smooth animations, and an omnibar (Vomnibar) for search, history, bookmarks, and command execution. The Vomnibar is a rich UI component that communicates with the background via port messaging. The extension supports multiple browsers (Chrome, Firefox, Edge) and both Manifest V2 and V3, with extensive version-specific conditionals and polyfills. The build system uses TypeScript, gulp, rollup, and terser to produce optimized builds, and includes custom patches to vendored TypeScript and Terser. The codebase demonstrates high engineering effort in handling complex browser quirks and performance optimization, but also carries technical debt from accumulated workarounds and legacy browser support.
react-dropdown-tree-select is a React component library that provides a dropdown interface for selecting items from hierarchical tree data. The component supports multiple selection modes (multi-select, simple select, radio select, and hierarchical), displays selected items as tags/pills, includes search functionality with progressive filtering and debouncing, offers keyboard navigation, and implements accessibility features through ARIA attributes. The architecture centers around a DropdownTreeSelect component that uses a TreeManager to handle tree state and operations, with supporting components for rendering trees, nodes, tags, and controls. Performance optimizations include virtualized rendering via react-infinite-scroll-component, search debouncing, and progressive filtering that reduces search scope with each keystroke.