Virtual object models

Document DOM model is not memory places, but is created on-demand while accessing particular nodes.

combines event-based and tree-based processing advantages (speed and comfort)

Implementation is the Sablotron processor for example (see http://www.xml.com/pub/a/2002/03/13/sablotron.html or http://www.gingerall.org/charlie/ga/xml/p_sab.xml)