Installation
The easiest way to install Less on the server, is via npm, the node.js package manager, as so:

$ npm install -g less
Command-line Usage
Once installed, you can invoke the compiler from the command-line, as such:

$ lessc styles.less
This will output the compiled CSS to stdout. To save the CSS result to a file of your choice use:

$ lessc styles.less styles.css
To output minified you can CSS use clean-css plugin. When the plugin is installed, a minified CSS output is specified with --clean-css option:

$ lessc --clean-css styles.less styles.min.css
To see all the command line options run lessc without parameters or see Usage.