DNSChecker.org - Check DNS Propagation worldwide. DNS Checker provides name server propagation check instantly. Changed nameservers so do a DNS lookup and check if DNS and nameservers have propagated.
DomainTools - Domain name research, including comprehensive Whois Lookup, Reverse Whois Lookup and Whois History.
Whats My DNS - Instantly check your domain names current IP address and DNS record information against multiple name servers located in different parts of the world.
APISpot.io - Bulk WHOIS and Domain Names API on steroids, Parsed and in JSON, Domain Availability Check, Domain and WHOIS Lookup
WhatsMyDNS.ME - WhatsmyDNS provides free DNS Resolution Check for checking if your DNS Records are updated in the various locations worldwide.
Domain Details - Displays Server Type, Headers, IP Address, Location Flag, and links to Whois Reports.