asset_hat 是 Rails 框架的扩展，用于优化 css 和 js ，提升二者的加载性能。
Minifies, bundles, and optimizes CSS/JS assets ahead of time (e.g., on deploy), not at runtime. Loads popular third-party JS (like jQuery, YUI, and Ext JS) from localhost in development, and auto-switches to Google's CDN in production. Lets you switch on LABjs to load more scripts in parallel. Can rewrite stylesheets to use CDN hosts (not just your web server) and cache-busting hashes for updated images.
项目主页：https://github.com/mintdigital/asset_hat
来自:开源中国社区
