Btw - I want a list of other operating systems with no IPv6 support, please enlighten me.
We are using Windows Server 2008 and Linux but all our servers and embedded products are IPv4 only. However, they dont have to reach anything in Internet. It is enough I can reach them via Internet.
Works for me and so far none of our customers asked IPv6 configuration for our servers. Our embedded products are not even capable to use IPv6 addresses even when they are running in Linux... (4 byte IP address is hardcoded to too many places...)
So in the end question is not if the OS supports IPv6 but is the software supporting IPv6... unfortunately it often doesnt.