kSpaces "...is a metadata-driven, distributed knowledge management platform. It was designed to be lightweight, transparent and extensible...kSpaces automatically tags files through the use of plugins. The two autotagging plugins that are included analyze a file's ID3 and EXIF headers, and then generate the appropriate RDF metadata.
Metadata associated with a file can be viewed and edited through the kSpaces Node application, supported by editor plugins. Five editor plugins have been included in the proof-of-concept, four of which are read only. These plugins allow the management of a subset of Dublin Core metadata, EXIF metadata, ID3 metadata and kSpaces-specific metadata. The Raw RDF plugin shows the raw RDF metadata associated with a knowledge asset."
Cool, an extensible metadata extrator.