International iVirtual iObservatory iAlliance
IVOA Registry of Registries

ivoa.net
Register/Validate a Registry Guide for Registry Providers Registry Specifications IVOA Registry Working Group

Searchable Registries

These registries claim to harvest from publishers regularly and therefore should have records for all resources known in the VO.
STScI Searchable Registry
IVOA Identifier: ivo://archive.stsci.edu/nvoregistry
Search service endpoint: http://vao.stsci.edu/directory/ristandardservice.asmx?

STScI Searchable Registry
IVOA Identifier: ivo://archive.stsci.edu/nvoregistry
RegTAP service endpoint: http://vao.stsci.edu/regtap/tapservice.aspx

EURO-VO Full Harvestable Registry
IVOA Identifier: ivo://esavo/registry
Search service endpoint: http://registry.euro-vo.org/services/RegistrySearch

GAVO RegTAP Service
IVOA Identifier: ivo://org.gavo.dc/rr/q/create
RegTAP service endpoint: http://dc.zah.uni-heidelberg.de/tap

GAVO RegTAP Service (Paris Mirror)
IVOA Identifier: ivo://purx/rr/q/create
RegTAP service endpoint: http://voparis-rr.obspm.fr:80/tap