Harp is a zero-configuration static web server and static site generator. It serves Jade, Markdown, EJS, Less, Stylus, Sass, and CoffeeScript files as HTML, CSS, and JavaScript without any build step. The architecture is a Connect-based middleware stack with a CLI wrapper. Key entry points are the `harp` CLI (bin/harp) and the library API (lib/index.js) which exposes `server()`, `compile()`, `mount()`, and `pipeline()`. The system reads project configuration from `harp.json` or `_harp.json`, supports layouts and partials via `_layout.jade` and `_data.json` files, and provides fallback 200/404 handling. It can compile projects to static assets for deployment. The codebase is well-structured with comprehensive tests and a smoke test for release validation. Dependencies are pinned, and the code uses modern JavaScript. It is a mature, stable project suitable for rapid prototyping and static site hosting.