SCSS is a preprocessor scripting language that extends the capabilities of CSS by adding features such as variables, nesting, and mixins. It allows developers to write more efficient and maintainable CSS code, and helps to streamline the development process by reducing repetition and increasing reusability.

ESLint is a linter for JavaScript that analyzes code to detect and report on potential problems and errors, as well as enforce consistent code style and best practices, helping developers to write cleaner, more maintainable 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.

TypeScript is a superset of JavaScript, providing optional static typing, classes, interfaces, and other features that help developers write more maintainable and scalable code. TypeScript's static typing system can catch errors at compile-time, making it easier to build and maintain large applications.