asset_hat

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.