Ipv6-address-test is a project mainly written in PHP, it's free.
IPv6 address recognition test suite, adapted from various sources
Credit for the original test suite goes to:
Rich Brown [email protected]
Converted from:
http://download.dartware.com/thirdparty/test-ipv6-regex.pl
(more people are credited in that file)
I've added a couple PHP-specific tests to the suite, including testing the 'filter' extension as well as inet_pton.