IPv6 transition mechanisms
ipv6 has been around nearly a decade. any company that doesnt have a competent dual-stack implementation deserves what they get. that having been said the number of vendors that recoil in shock and horror when you ask if they can route, or even support ipv6 is amazing.
The truly terrifying thing is the amount of otherwise competent and knowledgeable IT professionals who are utterly terrified of IPv6 and get elevated blood pressure whenever its mentioned.
Theres a whole generation of IT pros who have come to believe that NAT is the solution to almost all of their security issues, have no use for port blocking firewalls or defense in depth. It wasn't that long ago that desktop workstations often had Internet routeable IP addresses and you had to have actual firewalls on the front end and inside as well.
Nowadays they run their webserver in an RFC1918 range and use DNAT to send the traffic into it, thinking this is more secure than having a firewall and, when they look at IPv6, they see this security blanket as being taken away from them and they retreat into their shells.