  The increase in the amount of data on the Internet has led to the development
of a new generation of applications based on selective information
dissemination where, data is distributed only to interested clients. Such
applications require a new middleware architecture that can efficiently match
user interests with available information. Middleware that can satisfy this
requirement include event-based architectures such as publish-subscribe
systems. In this demonstration paper we address the problem of semantic
matching. We investigate how current publish/subscribe systems can be extended
with semantic capabilities. Our main contribution is the development and
validation (through demonstration) of a semantic pub/sub system prototype
S-ToPSS (Semantic Toronto Publish/Subscribe System).
