COMMUNICATIONS OF THE ACM
Departments

5 CEO’s Letter

On the 10th Anniversary of ACM’s Digital Library By John R. White

7 Executive Editor’s Corner Jim Gray: Humble Visionary By Diane Crawford

8 Letters To The Editor

Even Science Would Benefit from Auctions

10 CACM Online

A First Look at the Redesigned Site

96 Careers

Last Byte

112 Puzzled Circular Food By Peter Winkler

News

11 Damage Control

The U.S. patent system is overdue for reform, but what needs fixing, and how, is a matter of some dispute. By Leah Hoffmann

14 Analyzing Online Social Networks Social network analysis explains why some sites succeed and others fail, how physical and online social networks differ and are alike, and attempts to predict how they will evolve.

By Bill Howard

Viewpoints

22 Economic and Business Dimensions Search Engine Advertising Examining a profitable side of the long tail of advertising that is not possible under the traditional broadcast advertising model.

By Avi Goldfarb and Catherine Tucker

25 Privacy and Security

A Multidimensional Problem

It’s not just science or engineering that will be needed to address security concerns, but law, economics, anthropology, and more. By Susan Landau

27 Legally Speaking

Quantafying the Value of Patent Exhaustion

Should patents confer power to restrict reuses and redistributions of products embodying the whole or essential parts of inventions?

By Pamela Samuelson

31 Education

Reprogramming College Preparatory Computer Science

The college preparatory computer science education curriculum must be improved, beginning with the earliest phases of the process. By Joanna Goode

Practice

34 Real-World Concurrency

What does the proliferation of concurrency mean for the software you develop?

By Bryan Cantrill and Jeff Bonwick

40 Software Transactional Memory: Why is it Only a Research Toy? The promise of STM may likely be undermined by its overheads and workload applicabilities. By Călin Cas˛ caval, Colin Blundell, Maged Michael, Harold W. Cain, Peng Wu, Stefanie Chiras, and Siddhartha Chatterjee

47 CTO Roundtable on Virtualization Virtualization technology is hot again, but for the right reasons? By Mache Creeger, Moderator

17 The Limits of Computability Computational complexity and intractability may help scientists better understand how humans process information and make decisions.

By David Lindley