Express.js is a simple Node.js framework for single, multi-page, and hybrid web applications.

Grunt is a popular JavaScript task runner that automates repetitive tasks like minification, compilation, and testing, allowing developers to focus on writing code.

Pug is a high-performance template engine for Node.js and browsers that enables developers to write HTML templates using a concise and intuitive syntax. It supports a range of features, including template inheritance, conditionals, loops, mixins, and more, and can be easily integrated into a variety of web frameworks and build tools.