Geodex.org is an implementation of Project 418. That is, it is simply one way in this the web architecture patterns used in P418 could be used to develop an end user experience.
For some examples of this, try some of the other interfaces linked below and also check out the Notebook repository. for some R and Jupyter examples.
Also available: Triples entities by provider
The real stars of P418 are unquestionably the community of data providers. See the About section for a list of link to their sites.
For further details on the guiding principles of P418 we suggest the posting by Google: Facilitating the discovery of public data sets by Natasha Noy and Dan Brickley.
Further information and links is available in the Project 418 Publishing Notes
Web services that expose elements of the generated indexes are defined via SWAGGER
Project 418 (named for April 2018 when the project ends) leverages off patterns explored by the EarthCube Council of Data Facilities (CDF) Registry Working Group (RWG).
Some key elements of this approach will include: Leverage web architecture approaches to allow access to self hosted semantic metadata
This leverages HTML-5 microdata approaches combined with the schema.org vocabulary extended with community vocabularies/ontologies following established external vocabulary practices established by the schema.org governance. Generate indexes of this metadata following web architectural approaches to harvesting
Tech notes: The harvesting will follow web architecture practices as well. This leverages hypermedia patterns that are present as part of the web architecture to provide approaches to navigating networks of semantic metadata. These indexes would provide textual, spatial and graph representations of the exposed semantic metadata. Facilities would expose information about data and service resources for the initial phase
Tech notes: Key types exposed will include schema.org/DataSet and schema.org/DataCatalog leveraging work with schema.org led by RPI to establish these key types. Additionally work by the CDF RWG leveraging re3data resources will provide guidance on exposing information about a facility in general and also related to service endpoints (RESTful, OGC, others). This will be done following HTML5 microdata approaches using JSON-LD as a publishing approaches.