How is ontology different from expert systems and other AI technologies?
For the semantic web and modern ontology technology to function, computers must have access to structured collections of information and sets of inference rules that they can use to conduct automated reasoning. Artificial Intelligence researchers have studied such systems since long before the Web was developed. Knowledge representation, as this technology is often called, is currently in a state comparable to that of hypertext before the advent of the Web: it is clearly a good idea, and some very nice demonstrations exist, but it has not yet changed the world. It contains the seeds of important applications, but to realize its full potential it must be linked into a single global system. The OWL language is a major step towards developing that potential.
