Every time you exchange e-mail with a friend, check your bank statement online, or run a Google search, you are benefiting from MIT Institute Professor Barbara Liskov's research. Her pioneering contributions to software design earned Liskov the 2008 Turing Award, one of the highest honors in science and engineering.

Liskov is only the second woman to receive the prize, which carries a $250,000 purse and is often described as the "Nobel Prize of computing." The Association for Computing Machinery, which awards the honor each year, credited her with "foundational innovations" in the field of computer science and lauded her for helping make software more reliable, consistent, and resistant to errors and hacking.

Liskov's early innovations underlie every important programming language since 1975, including Ada, C++, Java, and C#. She not only invented data abstraction, a valuable technique that helps programmers focus on conceptual goals instead of the low-level complexities of code, but was a leader in demonstrating how it could be used to make software easier to construct, modify, and maintain. Many of these ideas were derived from her experience at the defense contractor Mitre in building the Venus operating system, a small, interactive time-sharing system.

As one of the first U.S. women to receive a PhD in computer science (from Stanford, in 1968), Liskov has watched from a front-row seat as computers reshaped society. Computer science is on considerably firmer footing now than it was back then, she says, but there's still a great deal of work that remains to be done.

"When I started, most of the field was unexplored and there were obvious problems everywhere--lots of low-hanging fruit, but also very fundamental issues that were poorly understood and very confusing," she says. "There are still many problems to work on, but now this work happens in the context of all that has gone before."

Liskov heads the Programming Methodology Group in the Computer Science and Artificial Intelligence Laboratory at the Institute where she has conducted research since 1972. Last year she was named an Institute Professor, the highest honor that can be granted to an MIT faculty member.