I've modified the W3C validation tool to work w/ IPv6. Right now I only have the HTML/XHTML validator up. You can use this to validate IPv4/IPv6 and nonSSL/SSL sites in any combination, but note that if your site is dual-stack, it will silently pick the IPv6 version by default. The host it is running on is WinXP SP2, Apache 2.0.55 dual-stack version, with ActiveState Perl. The only code that I changed to make it work with IPv6 was the Perl library. I also had to download and compile a few packages not included with the ActiveState Perl. So, to be honest, the W3C validation tool wasn't modified. Future plans: A logo to show whether or not your site is being accessed via IPv4 or IPv6 An option to select method of access ... IPv4 or IPv6 An option to validate using both methods ... useful for dynamic pages that have different content based upon protocol. Full documentation on all modifications needed. Once this is done, I'll send the updates back to W3C, and see what they do with them. Access the site at: http://ipv6.jzylstra.com/validator/ [IPv6 only] Please note, there are no promises on this site being up at all times, nor promises about the speed. But it does work. For example, the site http://www6.wlug.org.nz/ [IPv6 only ] is XHTML 1.0 Transitional, but the W3C site [validator.w3.org] can't even connect to it. Jonathan A. Zylstra