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.

Wro4j Extensions

Strongly Typed Javascript:Generator

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

Gradle JS Plugin

A Servlet wrapper for LESS (http://lesscss.org). LESS extends CSS with: variables, mixins, operations and nested rules.

vraptor-js-controller helps interaction through ajax

Ginere static site generation from templates

Provides JS minification capabilities.

Maven SpiffyUI Plugin