About the Authors

John R. Levine was a member of a computer club in high school — before high school students, or even high schools, had computers — where he met Theodor H. Nelson, the author of Computer Lib/Dream Machines and the inventor of hypertext, who reminded us that computers should not be taken seriously and that everyone can and should understand and use computers.

John wrote his first program in 1967 on an IBM 1130 (a computer somewhat less powerful than your typical modern digital wristwatch, only more difficult to use). He became an official system administrator of a networked computer at Yale in 1975. He began working part-time — for a computer company, of course — in 1977 and has been in and out of the computer and network biz ever since. He got his company on Usenet (the Internet’s worldwide bulletin board system) early enough that it appears in a 1982 Byte magazine article on a map of Usenet, which then was so small that the map fit on half a page.

Although John used to spend most of his time writing software, now he mostly writes books (including UNIX For Dummies and technical books such as Linkers and Loaders and qmail) because it’s more fun and he can do so at home in the tiny village of Trumansburg, New York, where in his spare time he was the mayor for several years and can hang around with his daughter when he’s supposed to be writing. John also does a fair amount of public speaking. (Go to www.johnlevine.com to see where he’ll be.) He holds a BA degree and a PhD in computer science from Yale University, but please don’t hold that against him.

In high school, Margaret Levine Young was in the same computer club as her big brother, John. She stayed in the field throughout college against her better judgment and despite John’s presence as a graduate student in the computer science department. Margy graduated from Yale and went on to become one of the first PC managers in the early 1980s at Columbia Pictures, where she rode the elevator with big stars whose names she wouldn’t dream of dropping here.

Since then, Margy has co-authored more than 25 computer books about topics that include the Internet, UNIX, WordPerfect, Microsoft Access, and (stab from the past) PC-File and Javelin, including The Internet For Dummies Quick Reference and UNIX For Dummies, and Windows Vista: The Complete Reference and Internet: The Complete Reference (both from Osborne/McGraw-Hill). She met her future husband, Jordan, in the R.E.S.I.S.T.O.R.S. (the computer club we mentioned). Her other passion is her children, along with music, Unitarian Universalism, reading, knitting, gardening (you can never grow too much garlic), and anything to do with eating. She lives in Vermont (see www.gurus.org/margy for some scenery) and works as the Web Team Manager for the Unitarian Universalist Association (www.uua.org).

Please visit both authors online at net.gurus.org.

Dedication

John and Margy dedicate this book to their father, Bob Levine, who after 93 years is still working hard to make the world a better place, and to the memory of Dionir de Souza Gomes Young.

Authors’ Acknowledgments

We thank Shelby Meyerhoff, social networker extraordinaire, for writing the chapters about Facebook and Twitter.

Colleen Diamond hustled us through the editorial process despite our attempts to drag it out while (no doubt at great personal cost) making us look like better writers than we are. Steve Hayes gets us organized, which is no easy task. Thanks also to the rest of the gang at John Wiley & Sons, especially those listed on the Publisher’s Acknowledgments page.

John thanks Tonia, and Margy thanks Jordan, for holding everything together. We all thank Bill Gladstone at Waterside Productions for encouragement. The entire contents of this book were edited and submitted to the publisher by using the web — practicing what we preach. We thank our Internet providers: Lightlink and Britghtworks Computer Consilting (Ithaca, New York — Hi, Homer! Hi, John!), and OTT Communications (Shoreham, Vermont).

Finally, thanks to all the smarties (we wouldn’t say wiseacres) who sent us comments about previous editions and helped make this one better. If you have ideas, comments, or complaints about this book, whisk them to us at [email protected].

Visit our website at net.gurus.org for updates and more information about the topics in this book.

Publisher’s Acknowledgments

Executive Editor: Steve Hayes

Project Editor: Colleen Diamond

Technical Editor: Doug Sahlin

Editorial Assistant: Claire Brock

Sr. Editorial Assistant: Cherie Case

Project Coordinator: Emily Benford

Cover Image: ©iStock.com/DSGpro