Neither XML is an "ultimate solution" to all problems of machine data exchange. Development goes on.
For interactive (rich) web applications (RIA) with intensive server-to-client communications, because of easier interpretability and smaller data, the formats such as JSON (JavaScript Object Notation) are used.
YAML is used for handwriting structured data.
These standards will be mentioned during lectures as well. The focus of the course is in XML, derived formats instruments for processing and applications.