XML Technologies Dissected

XML technologies are very popular, and one of the most important reasons for this is the availability of tools and technologies for working with XML, eliminating the need to build XML processing from scratch. However, XML technologies are built on top of inherent (and not always well-defined) information models, and this may cause problems because (1) the information models of some tools may not support the required "view" of XML, or (2) there is no appropriate data model to work with the information model in question. In this article, we approach this question from the systematic side, and describe the most prominent XML technologies with regard to their information and data models.