We care a lot about the health of the Internet. Recently, we've become increasingly concerned that IPv4 addresses — the numbers that computers use to connect to the Internet — are running out. Current projections place IPv4 address space exhaustion somewhere in late 2011, and while technologies such as Network Address Translation (NAT) can offer temporary respite, they complicate the Internet's architecture, pose barriers to the development of new applications, and run contrary to network openness principles.

That's why we're pleased to let you know that Google search is also available over IPv6 at ipv6.google.com (you'll need an IPv6 connection to view it). While IPv4 provides about four billion IP addresses — not enough to assign one to every one of Earth's more than six billion inhabitants — IPv6 provides enough address space to assign almost three billion networks to every person on the planet. We hope that by allowing every computer and mobile device on the network to talk to each other directly — an idea known as the "end-to-end principle" that was crucial to the original design of the Internet — IPv6 will allow the continued growth of the Internet and enable new applications yet to be invented.

With current operating systems such as Windows Vista, Mac OS X, and Linux providing high-quality support for IPv6, we hope it's only a matter of time before IPv6 is widely deployed. We will be doing our part.

Changed three million networks to three billion networks in the second paragraph.