Know what's in the toolbox

Native application programming language

A compiled language used for Apple-platform applications and other native software. Pair it with SwiftUI or UIKit for iOS interfaces and call platform SDKs directly.

Typed application programming language

A language with Java interoperability and coroutine support, used for native Android apps and other application targets. Pair it with Jetpack Compose for Android UI.

Typed superset of JavaScript

Adds static types and interfaces to JavaScript, then compiles away to plain JS. The payoff is editor autocomplete, safer refactors, and a whole class of runtime bugs caught before you ship.

Memory-safe systems language

A compiled systems language that guarantees memory safety at compile time without a garbage collector. Fast and predictable, at the cost of a steeper learning curve than most web languages.

JavaScript runtime

A JavaScript runtime built on V8, with Node APIs for servers, files, networking, and processes. Supported releases can execute erasable TypeScript through type stripping; application builds and type checking remain separate decisions.

All-in-one JavaScript runtime

A JavaScript runtime with an integrated package manager, bundler, and test runner. It transpiles TypeScript and JSX while executing them, and implements many Node APIs so existing packages can work with it.

Interpreted general-purpose language

A readable, batteries-included language that dominates data work and machine learning. On the web it shows up as API backends (FastAPI, Django) and anywhere ML models need serving.

Compiled object-oriented platform

Microsoft's cross-platform runtime and C# language, open source and running on Windows, macOS, and Linux. Strong for large backends, desktop apps, and games through Unity.

Shopify storefront toolkit

Shopify-aware components and utilities for custom React Router storefronts. Provides commerce building blocks so developers can focus on the shopping experience.

Component-based UI library

Meta's library for building UIs from components written in JSX. It is a UI layer, not a full framework, so routing, data fetching, and builds come from the tools you pair it with.

Progressive frontend framework

A frontend framework built around single-file components (`.vue`) and built-in reactivity. More batteries-included than React out of the box, with an official router and state library.

Compiled UI framework

A UI framework that compiles declarative HTML, CSS, and JavaScript components into browser code. Use Svelte for components; SvelteKit adds application routing, server rendering, and deployment adapters.

Svelte application framework

Builds applications around Svelte components with routing, server loads, endpoints, and form actions. Choose rendering per route and an adapter for the host you deploy to.

React meta-framework

A React application framework with routing, static and request-time rendering, Server Components, and route handlers. App Router separates server work from interactive client components.

Content-first web framework

Renders content pages to static HTML by default, with optional interactive islands and adapter-based request-time rendering. Content collections load local or remote content and validate its schema.

Native mobile UI from React

Meta's framework for building iOS and Android apps with React. Components render to real native views, and most logic is shared across both platforms.

React Native framework and cloud services

The framework layer on top of React Native: an SDK of device APIs, file-based routing with Expo Router, and EAS cloud services that build, submit, and update apps without local Xcode or Android Studio setup.

Cross-platform desktop framework

Builds desktop (and mobile) apps from a web frontend plus a Rust backend. It uses the operating system's own webview instead of bundling Chromium, so installers are far smaller than Electron's.

Desktop apps from web tech

Bundles Chromium and Node.js so a web app runs as a desktop app with full system access. Rendering is identical on every OS because the browser ships with the app.

Python web framework for APIs

Builds HTTP APIs from Python type hints: requests are validated automatically, and an OpenAPI schema with interactive docs is generated for free. Supports async handlers.

Structured Node.js server framework

A TypeScript framework for server-side apps built from modules, controllers, and providers wired by dependency injection. Validation, guards, OpenAPI docs, GraphQL, and rate limiting come as first-party packages.

Fast Node.js web framework

A low-overhead Node.js web framework with JSON Schema validation and serialization built in, and a plugin system for everything else.

Web-standards web framework

A small web framework built on the standard Request and Response APIs, so the same code runs on Cloudflare Workers, Bun, Deno, Node.js, and serverless platforms. Middleware, a typed RPC client, and Zod-based OpenAPI are available.

Postgres backend-as-a-service

A Postgres backend platform with Auth, Storage, Realtime, Edge Functions, and generated data APIs. Use its managed service or self-host the open-source components; browser data access needs deliberate grants and Row Level Security policies.

Relational SQL database

A mature, standards-compliant relational database with strong JSON support and a large extension ecosystem, including PostGIS for geospatial data and pgvector for embeddings.

In-memory key-value store

An in-memory data structure store used as a cache, session store, rate limiter, queue, and pub/sub broker. Responses are typically sub-millisecond because data lives in RAM.

TypeScript ORM

Define your schema in one file and Prisma generates a fully typed client plus migrations. A renamed column becomes a compile error instead of a runtime failure.

TypeScript SQL query builder

A lightweight ORM whose query API mirrors SQL, with schemas written in TypeScript. Small runtime footprint and a good fit for serverless and edge environments.

Vector search engine

An open-source vector database written in Rust, with payload filtering alongside similarity search. Self-host it or use the managed cloud.

Embedded analytical database

A columnar SQL engine that runs in-process, like SQLite but built for analytics. Queries CSV and Parquet files directly and handles large local datasets quickly.

TypeScript auth library

A TypeScript authentication library with email/password, social sign-in, sessions, database adapters, and plugins for organizations, two-factor auth, and passkeys. In database-backed deployments, its auth tables live in the database you configure.

Authentication server and Supabase service

Authentication with client SDKs, password and social sign-in, magic links, and JWT sessions. User records live in a Postgres auth schema; tokens integrate with Supabase's Data API and Row Level Security policies.

Python SQL toolkit and ORM

Python's standard database toolkit: a Core layer for composing SQL and an ORM for mapping classes to tables. Works with Postgres, MySQL, SQLite, and more, with sync and async APIs.

Database migrations for SQLAlchemy

Versioned schema migrations for SQLAlchemy projects. It can autogenerate a migration by diffing your models against the database, which you then review and commit.

Python data validation

Validates and parses data using Python type hints. FastAPI uses it for request and response models; version 2's core is written in Rust for speed.

CRDT library for shared data

Represents shared documents as CRDTs, so edits from any number of clients merge automatically without conflicts or a central lock. Providers sync it over WebSockets, WebRTC, or IndexedDB for offline use.

Collaboration server for Yjs

A WebSocket server for Yjs documents from the Tiptap team. Extensions handle authentication, persistence to your database, Redis fan-out across instances, and webhooks.

Admin dashboard template

A polished, MIT-licensed dashboard template built on Bootstrap 5, with hundreds of responsive components, an icon set, and dark mode.

Admin dashboard template

One of the longest-running open-source admin templates. Version 4 moves to Bootstrap 5 and drops the jQuery requirement.

Declarative Android UI toolkit

Android's Kotlin UI toolkit: composable functions describe screens from state and can interoperate with existing Views. Keep data operations outside rendering and test lifecycle behavior.

Copy-into-your-repo components

Not a package you install but a set of React components you copy into your project with a CLI, built on accessible primitives and Tailwind. You own and edit the code directly.

Utility-first CSS framework

Style directly in markup with small single-purpose classes like `flex`, `px-4`, and `rounded-lg`. Unused classes are stripped at build time, so the shipped CSS stays small.

Tailwind component plugin

A Tailwind plugin that adds semantic component classes like `btn`, `card`, and `navbar`, plus themes. Cuts class clutter while keeping Tailwind underneath.

React component library

A batteries-included React library with 100+ components, a hooks package, form management, modals, notifications, and dark mode built in.

Enterprise React design system

A design system from Ant Group aimed at data-heavy business software, with especially capable tables, trees, filters, and forms.

Headless accessible primitives

Unstyled React primitives (dialogs, dropdowns, popovers, tabs) that handle focus management, keyboard navigation, and ARIA for you. You bring all the styling.

Headless accessible components

Tailwind Labs' set of unstyled, accessible components for React and Vue, designed to pair with Tailwind classes.

Vue component framework

A complete Material Design component framework for Vue, with a broad set of layout and form components.

Headless rich-text editor

A headless rich-text editor framework built on ProseMirror, for React, Vue, and plain JavaScript. Its collaboration extension binds the editor to a shared Yjs document.

Frontend build tool and dev server

Serves source files as native ES modules during development, so the dev server starts almost instantly and hot module replacement stays fast as the project grows. Bundles for production.

AI coding agent

OpenAI's coding agent, available as an open-source CLI and as a cloud agent that works on tasks in parallel sandboxes.

Container platform

Packages an app with its dependencies and configuration into a container image that runs the same on a laptop, CI, and production.

JavaScript package manager

A package manager that stores each package version once on disk and links it into projects, making installs fast and space-efficient. Its strict node_modules layout blocks imports of undeclared dependencies.

Monorepo build system

Runs tasks across a JavaScript monorepo in dependency order and caches the results by content hash, so unchanged packages are skipped locally and in CI. Remote caching shares results across machines.

Versioning and changelogs

Contributors add small changeset files describing what changed and how big the change is; Changesets turns them into version bumps and changelog entries across every package in a monorepo.

Electron packaging and updates

Packages an Electron app into installers for Windows, macOS, and Linux, handles code signing and macOS notarization, and pairs with electron-updater for auto-updates.

Vite-powered test framework

A test runner for JavaScript and TypeScript with assertions, mocking, and coverage integration.

Browser automation and end-to-end testing

A browser testing toolkit for Chromium, Firefox, and WebKit, with locators, retrying assertions, and trace diagnostics.

User-centered UI testing utilities

DOM testing utilities focused on accessible roles, labels, and behavior visible to users.

Automated accessibility rules engine

An accessibility engine for automated checks of rendered web interfaces.

Open-source CMS

The PHP content management system behind a large share of the web: drafts, roles, revisions, a media library, and the block editor, extended by thousands of plugins and themes.

E-commerce plugin for WordPress

Turns a WordPress site into a store: products, carts, checkout, payments, and orders, managed from the same admin as the content.

3D rendering library

The most widely used JavaScript 3D library: scenes, cameras, lights, materials, and loaders over WebGL, with a WebGPU renderer alongside. It renders; physics, input, and game structure are up to you.

React renderer for Three.js

Write Three.js scenes as declarative React components. Pairs with the drei helper library for cameras, controls, loaders, and effects.

3D web engine

A full 3D engine started at Microsoft, with physics, a scene inspector, PBR lighting, WebXR, and WebGPU support built in.

3D game engine and editor

A WebGL/WebGPU game engine with a collaborative, browser-based visual editor. Games are built for the web first, with small builds that load fast on mobile.

2D game framework

A full 2D framework for browser games: scenes, sprites, tilemaps, input, audio, cameras, and built-in physics. The default choice for 2D HTML5 games.

2D rendering engine

A fast 2D renderer for WebGL and WebGPU. It draws sprites, text, and graphics very quickly but isn't a game framework — no built-in physics or scene flow.

Beginner-friendly 2D library

A small, fun-first JavaScript game library with a component-based API that gets a playable game on screen in a few lines. The community-maintained continuation of Kaboom.js.

Full game engine

A complete, MIT-licensed 2D and 3D engine with its own editor and scripting language (GDScript), plus C#. Exports to desktop, mobile, and the web.

Gradually typed scripting language derived from Lua

A language derived from Lua 5.1 with optional type checking, used for gameplay scripting in Roblox. Its language implementation is open source independently of the Roblox platform.

Visual novel engine

A story-focused engine with dialogue scripting, branching, screen language, saves, and Python for custom logic.

Lua framework for 2D games

A Lua framework supplying graphics, audio, input, and physics while leaving game structure and tools to the developer.

Physics engine

A 2D and 3D physics engine written in Rust and shipped to JavaScript as WebAssembly. Deterministic simulation, rigid bodies, joints, and character controllers.

Tilemap level editor

A free desktop editor for tile-based levels. Exports JSON and TMX maps that Phaser, Godot, and most 2D engines can load directly.

C# game framework

A code-first .NET game framework with graphics, input, audio, and a content pipeline. The team supplies game structure and authoring tools.

C game programming library

A compact C library providing windowing, drawing, input, audio, and 2D/3D APIs. You own the game loop and application structure.

Java game framework

A Java game framework with platform backends, rendering, input, audio, and asset handling. Shared game code still needs target-specific testing.

Design direction and critique skill

A design skill that pushes coding agents away from generic, templated UI. It ships named commands — shape, critique, audit, polish, animate, adapt, extract, live — and guidance on typography, spacing, OKLCH color, motion, and UX copy.

Design-engineering polish skill

Jakub Krehel's skill for the small details that make an interface feel finished: press feedback on buttons, balanced text wrapping, concentric border radii, shadows, hit areas, icon alignment, and restrained enter/exit animation.

UI review skill

Vercel's skill that reviews UI code against its Web Interface Guidelines — 100+ rules across accessibility, performance, and UX — fetching the latest rules before each run and reporting findings as file:line.

Accessibility audit skill

Part of Anthropic's open-source design plugin: runs a WCAG 2.1 AA audit on a design or page, covering color contrast, keyboard navigation, touch target size, and screen reader behavior.