Closure Compiler is a JavaScript optimizing compiler. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what's left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls. It is used in many of Google's JavaScript apps, including Gmail, Google Web Search, Google Maps, and Google Docs.

Minium Core

Maven plugin to compress and merge resources like JavaScript and CSS files.

Twibs: Core Libraries

WebUtilities is the Java library that helps you to speed up and improve client side performance of your J2EE web application.

The Google Closure plugin