This is the Grails Resources framework. It provides a DSL for declaring static resources in plugins and in apps, and a mapper artefact that allows other plugins to provide processing of static resources to e.g. minify / zip them. All processing is performed at runtime once, against files in the server filesystem. Built-in mappers included in the plugin: * CSS rewriter (two mappers required, happens automatically) * Bundler (combines multiple css or js files into one) See docs at http://grails.org/plugin/resources