The Web and the Semantic Web, as we see it, can be understood as a
"living organism" combining autonomously evolving data sources,
each of them possibly reacting to events it perceives. Rather than
a Web of data sources, we envisage a Web of Information Systems,
where each such system, besides being capable of gathering
information (querying persistent data, as well as "listening" to
volatile data such as occurring events), is capable of updating
persistent data, communicating the changes, requesting changes of
persistent data in other systems, and being able to react to
requests from other systems. The dynamic character of such a Web
requires declarative languages and mechanisms for specifying the
evolution of the data.
In this course we first talk about foundations of evolution and
reactive languages in general, and then concentrate on some
specific issues posed by evolution and reactivity in the Web and in
the Semantic Web.