W3C API contains the list of W3C groups, and the list of W3C published specifications.
GitHub provides a REST API and a GraphQL API. It contains list of repositories and issues. w3c/github-cache does provide a cache for some information, exposed through labs.w3.org.
common-labels.json contains the list of horizontal repositories, used for review requests and horizontal issues tracking.
@@WHATWG
@@IETF
@@WPT
@@ASH-NAZG
Curated sources provide data that has been curated automatically (such as dropping invalid JSON files) and manually (such as patching raw data or complementing raw data).
w3c/groups contains repositories.json, to associate a github repository with a set of W3C groups. The crawler, w3c/groups-server, processes w3c.json files with various GitHub organizations.
browser-specs contains index.json, to associate the URL of a specification, with its groups (W3C, WHATWG, IETF, etc.), shortname, github repository, etc.
webref contains index.json and idlnames, to associate a specification with its IDL definitions.