Less is a meta-language on top of css that’s used to describe the style of a document cleanly and structurally, with more power than flat css allows. less both provides a simpler, more elegant syntax for css and implements various features that are useful for creating manageable stylesheets.

less.js is the reference implementation of less, written in javascript.

this package contains the less library for node, and the script lessc for statically compiling less into css.