WinSock Development Information
Sample programs, technical articles, links, and an extensive WinSock error reference. (Bob Quinn)
Windows Sockets Programming
Links to get started with WinSock programming. (Ed Snible)
Windows Sockets 2
Developer documentation of Winsock for all Windows platforms.
TCP/IP Raw Sockets
MSDN documentation about Raw Socket specification. Raw sockets can be used to create your own protocols.
sockaddr.com
Programming Resources for WinSock 1.1 and 2 including sample programs, specifications, and links. (Lewis Napper)
RFC 2292: Advanced Sockets API for IPv6
Defines some the advanced features of the sockets API that are required for applications to take advantage of additional features of IPv6.
FreeBSD: Sockets
FreeBSD Developers' Handbook chapter about using sockets