HTML templates are pre-designed and pre-built web pages that can be customized and used as a basis for building websites. They often include common elements such as headers, footers, menus, and content sections, and can be easily edited using HTML and CSS to fit specific branding and content needs.

Webpack is a popular open-source module bundler for JavaScript applications that bundles and optimizes the code and its dependencies for production-ready deployment. It can also be used to transform other types of assets such as CSS, images, and fonts.

Gulp.js is an old but popular site building tool that automates various repetitive development tasks in web development, such as compiling Sass, minifying JavaScript, and optimizing images.

RollupJS is a popular and efficient JavaScript module bundler that takes the code from multiple modules and packages them into a single optimized file, minimizing the overall size of the application and improving its performance.

Web components provide a way to create reusable, encapsulated UI components using standard web technologies such as HTML, CSS, and JavaScript. They allow developers to create complex UI components that can be easily shared across multiple projects and frameworks. Web components are built using four main specifications: Custom Elements, Shadow DOM, HTML Templates, and ES Modules.