ARIN is the American Registry for Internet Numbers, the organisation that hands out the blocks IP addresses.
Each region has its own, for instance Australia/Pacific has APNIC. Naturally, they work very closely together.
Open Query can assist you with planning and deployment of IPv6 capabilities on your front-end servers, as well as at the back-end if you wish. Not all hosting providers support IPv6, but many good ones do. MySQL/MariaDB can operate in a native IPv6 or dual stack environment. Open Query enabled its own front-end servers for IPv6 a number of years ago already.
ARIN has reached depletion of the general IPv4 free pool today, 24 September 2015. We’ve been talking about the inevitability of IPv4 depletion for many years and have been educating the community about the need to get IPv6 resources and prepare public facing services for the IPv6 Internet, and now is the time to make sure you are taking steps toward preparing for IPv6 as soon as possible.