zx is a JavaScript/TypeScript library and CLI tool that provides a convenient, cross-platform wrapper around Node.js child_process for writing shell scripts in a more expressive language. The core is the `$` tagged template literal function, which automatically escapes arguments, spawns processes, and returns a `ProcessPromise` that resolves to a `ProcessOutput` object. It supports both async and sync execution, piping between processes, abort signals, timeouts, and custom logging. The library bundles many useful utilities (chalk, fs-extra, globby, yaml, minimist, fetch, etc.) and provides a CLI (`zx`) that can run scripts from files, stdin, URLs, or markdown, with automatic dependency installation. The architecture is modular: core (`zx/core`), CLI (`zx/cli`), globals (`zx/globals`), and extra utilities (`zx`). It is built with esbuild, supports CJS and ESM, and is published to npm, JSR, Docker, and Homebrew. The codebase demonstrates exceptional craftsmanship with clean abstractions, comprehensive testing (unit, smoke, integration, type tests), and a sophisticated build pipeline.