DOM (Document Object Model) is the standard in-memory XML representation. DOM proves flexible in that you can access any document bits whenever you want, but it can be memory hungry, so developers commonly use it to build client applications where memory is not an issue. DOM suffers from being old, language-neutral (so it is a lowest common denomin [..]

SAX (Simple API for XML) differs from DOM in that it is event-driven: the document flashes before your eyes while the parser notifies you of elements and attributes. You pick out the bits you want as it goes by. SAX is lightweight and simple, but working out your location in a document can be challenging. Developers generally use SAX in server appl [..]

JAXP (Java API for XML Parsing) is not really a technology separate from DOM or SAX, but simply an extension to both that makes them easier to use in Java. Both DOM and SAX are language-neutral, so neither answers questions like, "How do we create a parser." JAXP answers the creation question and is a standard API for XSLT (Extensible Sty [..]

To those struggling with DOM, JDOM will seem like a breath of fresh air. JDOM fixes some of DOM's more arcane areas. For example, unlike with DOM, in JDOM elements and attributes are objects, so you can call new Element("name");

Because DOM4J fixes the same DOM problems as JDOM, they have similar APIs. In fact, DOM4J was originally a fork from JDOM. They differ most in that DOM4J, like DOM, uses interfaces in some places where JDOM uses objects; consequently, in DOM4J, you need a factory to create elements, attributes, and so on. While that makes DOM4J slightly harder to u [..]

JAXB (Java API for XML Binding) offers a fresh method to parse XML documents. So fresh that the ink has yet to dry, so to speak. JAXB, not due for release until the end of 2002, is an in-memory model like the DOM variants, but the similarity with DOM ends there. With JAXB, you compile your DTD (document type definition) (or soon XML Schema) into Ja [..]

Namespaces let you mix tags from different sources without confusing their origin. Each element in a namespace acquires two extra bits of information.

XML lets you store arbitrary data in an organized manner, and it lets you design how to lay it out. Sometimes, however, you may wish to explain exactly how you laid things out.

XML Schema lets you define an XML document's contents similarly to DTDs, but XML Schema does not suffer from DTD's shortcomings.

XML Schema lets you define an XML document's contents similarly to DTDs, but XML Schema does not suffer from DTD's shortcomings.