Domain Checker for Mac

From Thomas Kuehner:

This little AppleScript application checks for existing domains silently in the background by testing if they are already hosted on a server in the internet. Domain Checker has a built-in list of 252 domain suffixes as listed in the file "Built-In Suffixes". You may add own suffixes to the file "Additional Suffixes". This file will be read by Domain Checker and added to the built-in list. After all entries have been processed you may choose to view the result file that lists all checked domains or to open all valid domains in your favorite web-browser (can be a huge job!).