Metadata or data exchange format directory (not only RDF/OWL ontologies)

Do you know any web-based collaborative directory/search engine for finding
data exchange formats? Not only OWL/RDF based, should also allow me to find
XML schemas, JSON templates or even CSV column templates.

What works/what doesn't?

How can you collaboratively use the format/ontology you found and build upon
it?

Regards,
Ricardo <http://about.me/rncabral>