The World Wide Web (WWW) incorporates a huge potential for collaborative wor k-ing.
This paper focuses on Web page annotations that can enhance group-working on
the Web drastically.
A model of Web page annotations is introduced that defines relations between the us-ers,
the Web pages and their annotations. It is taken together with technological re-strictions
of existing approaches to form a taxonomy and an overview of the state of
Our « active annotations » approach results from the observation that in current im-plementations
the temporal relations are left out. Active annotations are focused on
synchronous notification mechanisms within the Web and are implemented in the
platform-independent language Java. Their purpose is to support collaborative work
within small groups.