We argue that a roadmap for software engineering and the Internet currently should be based on standards for complex data and document structures, like the Extensible Markup Language (XML). In fact, XML and its cohort of related standards are likely to become an epochal innovation for designing Internet-based software systems. The fields of application of these new notations and related technologies are only limited by human imagination, and simply cannot be enumerated at the moment. Our interests currently concern a concept that we call declaratively active document, for which these standards offer an important support. In this paper we describe shortly the state of the art of these new standards, and how we are using the concept of declaratively active document for software engineering purposes.