HMPL is a server-oriented customizable templating language for JavaScript, serving as an alternative to HTMX and Alpine.js. It utilizes the Fetch API to send customizable requests from client to server, resulting in ready-made HTML components. HMPL is component-based, integrates with JSON5 and DOMPurify, and aims to reduce JavaScript file sizes while maintaining modern framework capabilities. It supports various attributes for requests, enhancing flexibility and efficiency in web applications.