There are some changes in the computing world since 1990 (the year the original was published), and Stevens has taken the opportunity to make a complete set of reference manuals for programmers of all skill levels. The first volume, Networking APIs: Sockets and XTI, covers everything you need to know to make your programs communicate over a network. Stevens covers everything from writing your program to be compatible with both Internet Protocol version 4 (IPv4) and IPv6, to raw sockets, routing sockets, User Datagram Protocol (UDP), broadcasting / multicasting, routing sockets, internal servers, and many more, plus a section that covers POSIX threads. Stevens also notes compatibility issues with different operating systems so that readers can make the code more portable, and it offers many suggestions about how to make the code more robust.