Google Dataset Search
"Dataset Search enables users to find datasets stored across thousands of repositories on the Web, making these datasets universally accessible and useful...
"Datasets and related data tend to be spread across multiple data repositories on the web. In many cases, information about these datasets is neither linked nor has it been indexed by search engines, making data discovery tedious or, in some cases, impossible.
By providing our users with a single interface that allows them to search across multiple repositories, we hope to transform how data is being published and used. We also believe that this project will have the additional benefits of a) creating a data sharing ecosystem that will encourage data publishers to follow best practices for data storage and publication and b) giving scientists a way to show the impact of their work through citation of datasets that they have produced."