Datasets - Mannheim Linked Data Catalog

twc-opendap

Linked Data Provenance for OPeNDAP data processing.
ichoose

SUNY Albany Center for Technology in Government I-Choose project
provenanceweb

Linked Data provenance and explanation.
Instance Hub (all)

Linked Data representations of common entities and concepts that occur in many datasets.

You can also access this registry using the API (see API Docs).