Modular Classloading System

 JBoss Modules is a standalone implementation of a modular (non-hierarchical)
 class loading and execution environment for Java. In other words, rather than
 a single class loader which loads all JARs into a flat class path, each
 library becomes a module which only links against the exact modules it depends
 on, and nothing more. It implements a thread-safe, fast, and highly concurrent
 delegating class loader model, coupled to an extensible module resolution
 system, which combine to form a unique, simple and powerful system for
 application execution and distribution.