Less.js is a dynamic stylesheet language that extends CSS with programming features like variables, mixins, and functions.
Less solves the problem of CSS's static nature by adding a preprocessing layer that compiles to standard CSS. The language introduces variables for reusable values, mixins for reusable style blocks, nested rules for cleaner organization, and functions for dynamic calculations. Developers write Less code that is then compiled down to plain CSS for browser consumption, allowing more maintainable and DRY stylesheets while remaining compatible with all CSS environments.
Less.js suits projects where stylesheets have grown complex or repetitive, particularly in larger applications where style reusability and organization matter. It works well for teams already comfortable with preprocessing workflows. The tool is appropriate for any project that can incorporate a build step, from single-page applications to traditional server-rendered sites. The official documentation at lesscss.org provides comprehensive guidance on language features and configuration.
The project maintains active continuous integration testing. The codebase uses Grunt for linting and testing, with contributors expected to add unit tests for new functionality. Development documentation is available separately, and the project maintains a detailed changelog tracking releases over time. Bug reports and feature requests are managed through the issue tracker, with documentation issues directed to a separate documentation repository.
