What design pattern to choose to map a big XML file to an in-memory object layer?

Say you want to parse a big XML file with a SAX parser. The XML file has a lot of namespaces, elements and attributes.

How to design a good class model and which design patterns should be used for it?

• The XML file could be from type XMI for example.
• The design should be independent of a specific programming language or framework.
• A big XML file means, a human cannot have an overview of the file to process it easily.