Bun

It covers the package manager that blows away npm on speed, the built-in HTTP server with WebSocket pub/sub, native SQLite and password hashing, and the bundler. The skill shows real patterns for serving files, running TypeScript without transpiling, and using Bun's file I/O APIs that are genuinely faster than Node. Use it when you're building anything in the Bun ecosystem or migrating from Node and want Claude to know about bun:sqlite, Bun.serve, and all the built-in stuff that makes Bun different. The examples are practical, the testing section is complete, and it doesn't pretend Bun is just another JavaScript runtime.