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.

Stylelint is a modern linter for CSS that helps you avoid errors and enforce consistent styling conventions. It provides rules for detecting errors and warnings, and can be configured to match your specific project's requirements.