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?

Good question. Until now, I still haven't found such a thing (web-based collaborative directory/search engine) for all data exchange formats. But I have a temporary solution, you could use Google with its "filetype" function.

For example, you could the following keywords to search about "university london" in OWL, RDF, and json formats:

university london filetype:owl OR filetype:rdf OR filetype:json

However, it does search by means of keywords, not semantic search. So, it's not a perfect implementation for a data search engine.

I'm not aware of a general-purpose directory. The closest thing that comes to mind is the SEMIC Asset Repository, a directory of e-government exchange formats in the context of the European Union.

I've also seen sites that provide a directory of UML/relational style schemas, but didn't look deep and don't remember the details. I've found them just by googling the obvious terms.