This NIP is not yet in main. Here is an overview of PRs referencing this NIP. 
NIP-60 Zap Gates - Interoperable distributed zap / pay walls  OPEN @Egge7
NIP-60 - Secure file load from URL OPEN @leandro21b
NIP-60 - Secure file load from URL CLOSED @leandro21b
NIP-53 - Nostr-based name registration system CLOSED @leandro21b