yazvs.pl is one of the utilities that Verisign uses daily to validate new versions of the root and arpa zones before they are published to the distribution masters. It performs the following steps:

• Read a candidate zone file from disk

• Validate KSKs using a locally configured trust anchor

• Validate ZSKs using KSKs

• Validate RRSIGs using ZSKs

• Retrieve the current zone data via AXFR

• Print a summary of the number of KSKs, ZSKs, DS, and RRSIG records that have changed

• Optionally produce a Unix diff of the two zones, excluding RRSIG/NSEC/NSEC3 records

More information here: http://yazvs.verisignlabs.com/