Less

Less is a CSS preprocessor that extends CSS with dynamic features like variables, mixins, functions, and nested rules. It allows developers to write more maintainable and reusable stylesheets by organizing CSS code in a structured, programmatic way. Less compiles into standard CSS that browsers can understand, either on the server-side during build processes or client-side using JavaScript. The preprocessor supports operations on colors, mathematical calculations, and conditional logic to generate CSS dynamically. Less is commonly used in large web projects where CSS complexity and maintenance become challenging with plain stylesheets. It has been integrated into popular frameworks and build tools like Bootstrap (which originally used Less before switching to Sass), Grunt, and Webpack. While Sass has become more dominant in recent years, Less remains widely used in existing projects and offers a gentler learning curve for developers new to CSS preprocessing.