For scientific information this doesn't exist; we have to do with tools like Google Scholar and Google Images. Both are pretty brilliant and allow you to filter on things, besides your regular keyword search. Of course, what we really need is an ontology-backed search, which Google seamlessly integrates under the hood, e.g. using the aforementioned schema.org.
Now, particularly for my teaching roles, I am frequently looking for material for slides, to support my message. Then, Google Images is great, as it allows me to filter for images that I am allowed to use, reuse, and even modify (e.g. highlight part of the image). Now, I know that some jurisdictions (like the USA) have more elaborate rules about fair use in education, but these rules are too often challenged and money, DRM, etc, limit those rights. Let alone scary, proposed European legislation (follow Julia Reda!).
So, I very much welcome this new effort! Search engine have a better track record than catalogs, like the Open Knowledge Foundation's DataHub. Of course, some repositories are getting so large, like FigShare, to a large extend by very active population by publishers like PLOS, they may soon become a single point of entry.