The Aura ubiquitous computing project is investigating how we can
reduce user distractions by having applications automatically adapt to
the s context. Context-aware applications rely on a shared service,
the Contextual Information Service, to obtain context information. In
this paper we describe our experience in implementing four very
different applications using the CIS and in porting the applications
to a different environment. One of the services also integrates
technologies developed by a sister project that focuses on using the
Semantic Web to support context awareness and privacy.