Document structures are a crucial mechanism for the creation and the usability of complex hypermedia documents. They form a possibility to deal with the inherent complexity of such documents and with document structures it is also possible to support the reuse of parts of hypermedia documents. In several theoretical approaches different kinds of document structures have been proposed. For example in the Dexter Hypertext Model or in the hypermedia model developed by Klaus Tochtermann. In the creation process of such hypermedia documents, which is strongly influenced by the offered functionality of the existing editors and tools, only simple kinds of structures could presently be used. Furthermore the use of hypermedia documents is often somehow connected to special system requirements, which makes it difficult to use these documents in a network. Especially the use of such hypermedia documents in the internet with all its different platforms and operating systems still cause many difficulties. The profit of hypermedia documents could obviously be increased, if broad forms of structuring could be used to build hypermedia documents and when these documents fulfill at the time the demands of interoperability and platform independency. This papers presents a contribution to this topic by introducing techniques for the implementation of structured hypermedia documents, which fulfill the demands of system and platform independency. These techniques are consequently based on the Extensible Markup Language. To form the basis for an XML-based implementation of structured hypermedia documents, the concepts of the Tochtermann model were transformed into a XML document type definition. Because we understand the process of creating a hypermedia document as an integrative process, not only the document type definition itself is described, but also the aspects of displaying such a XML-based hypermedia document. Due to the continuous use of XML conform techniques the developed HMDoc hypermedia documents are platform and system independent and can therefore be easily used in networks like the internet.