Open INTEL

https://www.openintel.nl/

Open INTEL is an active DNS database. It gathers information from public zone files, domain lists (Alexa, Umbrella), and reverse DNS entries. Once every 24 hours, data is collected about a bunch of DNS RRsets (SOA, NS, A, AAAA, MX, TXT, DNSKEY, DS, NSEC3, CAA, CDS, CDNSKEY). The data is openly available as AVRO files and dates back until 2016.

The data can be freely downloaded. There is documentation on the layout of the AVRO files.

The project is similar to Active DNS but seems to be larger in scope.