This paper introduces application profiles as a type of metadata schema. We use application profiles as a way of making sense of the differing relationship that implementors and namespace managers have towards metadata schema, and the different ways they use and develop schema. The idea of application profiles grew out of UKOLN's work on the DESIRE project (1), and since then has proved so helpful to us in our discussions of schemas and registries that we want to throw it out for wider discussion in the run-up to the DC8 Workshop in Ottawa in October. We define application profiles as schemas which consist of data elements drawn from one or more namespaces, combined together by implementors, and optimised for a particular local application.The experience of implementors is critical to effective metadata management, and this paper tries to look at the way the Dublin Core Metadata Element Set (and other metadata standards) are used in the real world. Our involvement within the DESIRE project reinforced what is common knowledge: implementors use standard metadata schemas in a pragmatic way. This is not new, to re-work Diane Hillmann’s maxim ‘there are no metadata police’, implementors will bend and fit metadata schemas for their own purposes. This happened (still happens) in the days of MARC where individual implementations introduce their own ‘local’ fields by using the XX9 convention for tag labelling. But the pace has changed. The rapid evolution of Rich Site Summary (RSS) has shown how quickly a simple schema evolves in the internet metadata schema life cycle.

The visions of SIOC (Semantically-Interlinked Online Communities) are: * To create an ontology that fully describes the content and structure of most online community sites - including not limited to weblogs, bulletin boards, mailing lists, newsgroups, etc. * To create new connections between discussion channels and posts, and to allow users to browse discussion data in interesting ways using these connections. * To overcome a "chicken-and-egg" problem with the Semantic Web (no applications without data, and no data without applications) by making it easy to generate and use SIOC data.

SWAML, pronounced [swæml], is a research project around the semantic web technologies to publish the mailing lists' archives into a RDF format.