CSS-JS-Booster is a PHP-script that tries to automate as many performance optimizing steps related to CSS and JS embedding as possible. For CSS these steps are: combine multiple CSS-files resulting in number of HTTP-requests going down minify CSS Embed any CSS-images smaller 24KB as data-URI or MHTML (for IE <= 7) Split the output back into 2 even files that can load in parallel (not for WP) GZIP-