The late W. Richard Stevens was the acclaimed author of UNIX® Network Programming, Volumes 1 and 2, widely recognized as the classic texts in UNIX networking; TCP/IP Illustrated, Volumes 1-3; and the first edition of this book. Stephen A. Rago is the author of UNIX® System V Network Programming (Addison-Wesley, 1993). Rago was one of the Bell Laboratories developers who built UNIX System V Release 4. He served as a technical reviewer for the first edition of Advanced Programming in the UNIX® Environment. Rago currently works as a research staff member in the Storage Systems Group at NEC Laboratories America.