General
IPv6 Network Programming
Listen for and accept TCP connections in C
Sockets-based Communication Using IPv6
Linux IPv6 HOWTO (en)
Programming using C-API
Socket programming and the C BSD API
Protocol Independent Programming
Convert an IP address to a human-readable string in C
DNS
Using Google Public DNS (with IPv6)
ipv6.google.com
Beej’s Guide to Network Programming
9.7. gethostbyname(), gethostbyaddr()
Manual Pages
Wikipedia
linux.die.net
man7.org
Question & Statements
How to support both IPv4 and IPv6 connections
FreeBSD: Interesting facts about AI_ADDRCONFIG
Tell whether a text string is an IPv6 address or IPv4 address using standard C sockets API
How to determine if a string is a valid IPv6 address in C++?
Timeout
Linux: is there a read or recv from socket with timeout?
Socket with recv-timeout: What is wrong with this code?
Does recv(…) operate this way?
RFC
RFC 3493 – Basic Socket Interface Extensions for IPv6, February 2003
RFC 4038 – Application Aspects of IPv6 Transition, March 2005