Anybody can share some light on companies that uses semantic web technologies? Currently at university have a semantic web class but I am finding it difficult where the use case are to create value for business or startup.
Facebook Open Graph crawlers use RDF in HTML head-meta elements conveying data about authors of web pages.
Similarly, Google Corporate Contacts extracts RDF from web pages (but can also use JSON microdata).
W3C's newly published open social standard is based on RDF (as JSON-LD) I believe.
RDF and SPARQL has lots of uses in libraries and bibliographic apps such as citation managers, as well as in publication of open data, in particular medical and bio informatics data.
Dublin Core (as RDF) is frequently used for standard document metadata, for example in PDF.
We use quite a bit of SPARQL to reason over medical ontologies. It's not exactly "semantic web", but ontological knowledge (such as the Gene Database, UMLS, etc) are naturally serialized in graphs, which makes them an excellent fit for RDF triplestores, hence SPARQL. We regularly query millions of concepts with billions of relations in milliseconds. True, RDF under the hood is just a EAV model, but thinking about the identity between triples, graphs, and logic programming makes a lot of sense for us.
Yes, for example at Wallix, we created awless.io a CLI for AWS, that uses RDF (https://github.com/wallix/triplestore) to model cloud data. So far this linked data has help us since it is loosely coupled and has graph-like properties.
I believe Schema.org uses (/can use?) linked data that e.g. Google can again use to provide more relevant information about your content: https://developers.google.com/schemas/
