.pug File — Pug Template

Pug (formerly Jade) is a high-performance template engine for Node.js that uses significant whitespace and a concise syntax to generate HTML. PUG files eliminate the need for closing tags, angle brackets, and much of HTML's verbosity — an element is defined by its tag name, followed by optional classes (.class), IDs (#id), and attributes in parentheses, with content after a space or on indented lines below. Pug supports mixins for reusable template blocks, includes for template composition, extends/block for template inheritance, conditionals, loops, and inline JavaScript. The format compiles to HTML and is used in Express.js applications, static site generators, and email template systems. Pug's concise syntax can represent complex HTML structures in significantly fewer lines than raw HTML. The engine was renamed from Jade to Pug in 2016 due to a trademark issue. While Pug's non-HTML syntax requires learning, developers who adopt it often find it dramatically more productive for writing HTML-heavy templates. The format supports filters for embedding other languages (Markdown, CoffeeScript) and can produce pretty-printed or minified HTML output.