When are two classes not the same? When they're loaded by different class loaders. This is just one of many curious side effects of Java's class-loading system. Binildas Christudas shows how different class loaders relate to one another and how (and why) to build your own custom class loader.
rating comment: The first part of the article is okay, it explains the basics of class loading and shows how class loaders work. The following parts of the article, mainly the example, is a little dry and too exhaustive. Overall it's good enough to give you a brief introduction to java class loading.