Astro is a new framework that aims to ship less client-side JavaScript by loading scripts only when needed. It comes with pre-configured renderers for popular frameworks like React, Vue, and Svelte, allowing users to build applications without installing these frameworks separately. Astro files are similar to HTML but contain extra JavaScript goodies, enabling powerful templates and components. The framework supports page-based routing, styling, and state management, although some features are still in early implementation. Astro also includes tools for styling, state management, and custom configurations, making it an attractive option for developers looking to build fast and efficient web applications.