So imagine you’ve got this image of two cats complete with a nice drop shadow. One half of the image has a white background, while the other half has no background (indicated by the standard Photoshop checkerboard background pattern).
So let’s say you’re using SpiderMonkey (the JavaScript engine from Mozilla) to build a Web application server that naturally uses JavaScript as the server-side language. Naturally, you want to support XML, since you want to be taken seriously and of course, you don’t want to write your own XML parser, because libxml2 is really good. And because you want to be extra cool, you want your XML implementation to support DOM level 3 out of the box. Read Garbage Collection in SpiderMonkey »