Abstract
OWL 2 extends the W3C OWL Web Ontology Language
with a small but useful set of features that have been requested by
users, for which effective reasoning algorithms are now available,
and that OWL tool developers are willing to support. The new
features include extra syntactic sugar, additional property and
qualified cardinality constructors, extended datatype support,
simple metamodeling, and extended annotations.
This document is a simple introduction to the new features of the
OWL 2 Web Ontology Language, including an explanation of its
differences with respect to OWL 1. It also presents the
requirements that have motivated the design of the main new
features, and their rationale from a theoretical and implementation
perspective.