CZDS
Also: Centralized Zone Data Service
ICANN's Centralized Zone Data Service, the single request point through which a researcher asks each generic top-level domain's registry operator for access to its zone file.
Approval is granted per TLD by each registry operator rather than in bulk, so coverage is an accumulation of individual approvals. The agreement behind that access forbids handing over a substantial portion of a zone and prohibits querying registries at scale.