Categories in this category are part of experimental initiatives. In general, they are populated by experimental templates or existing templates with new experimental functionalities, and their experimental statuses are thus dependent on that of their corresponding template.
This website uses the Wikivoyage API to get and display all the information you see. This is the MediaWiki API, which is a general API for accessing data from Wikimedia projects. You can find information about it here: MediaWiki API.