Professor Liskov, the first United States woman to earn a PhD from a computer science department, was recognized for helping make software more reliable, consistent and resistant to errors and hacking. She is only the second woman to receive the honour, which carries a $250,000 purse and is often described as the "Nobel Prize in computing".

"Computer science stands squarely at the centre of MIT's identity, and Institute Professor Barbara Liskov's unparalleled contributions to the field represent a MIT ideal: groundbreaking research with profound benefits for humankind. We take enormous pride that she has received the Turing Award", stated MIT President Susan Hockfield.

"Barbara Liskov pioneered some of the most important advances in fundamental computer science", stated Provost L. Rafael Reif. "Her exceptional achievements have lept from the halls of academia to transform daily life around the world. Every time you exchange e-mail with a friend, check your bank statement on-line or run a Google search, you are riding the momentum of her research."

Professor Liskov heads the Programming Methodology Group in the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT, where she has conducted research since 1972. Last year, she was named an Institute Professor, the highest honour awarded to an MIT faculty member.

"For nearly four decades, Barbara has been a seminal leader in programming languages and systems research at MIT, combining great intellectual insights with practicality", stated CSAIL Director Victor Zue, the Delta Electronics Professor in the Department of Electrical Engineering and Computer Science. "All of us at CSAIL are extremely pleased and proud of this latest accolade - the highest honour in computer science."

Professor Liskov's early innovations in software design have been the basis of every important programming language since 1975, including Ada, C++, Java and C#.

Professor Liskov's most significant impact stems from her influential contributions to the use of data abstraction, a valuable method for organizing complex programmes. She was a leader in demonstrating how data abstraction could be used to make software easier to construct, modify and maintain. Many of these ideas were derived from her experience at MIT in building the VENUS operating system, a small timesharing system that dramatically lowers the cost of providing computing and makes it more interactive.

In another contribution, Professor Liskov designed CLU, an object-oriented programming language incorporating clusters to provide coherent, systematic handling of abstract data types. She and her colleagues at MIT subsequently developed efficient CLU compiler implementations on several different machines, an important step in demonstrating the practicality of her ideas. Data abstraction is now a generally accepted fundamental method of software engineering that focuses on data rather than processes.

Building on CLU concepts, Professor Liskov followed with Argus, a distributed programming language. Its novel features led to further developments in distributed system design that could scale to systems connected by a network. This achievement laid the groundwork for modern search engines, which are used by thousands of programmers and hundreds of millions of users every day and which face the challenges of concurrent operation, failure and continually growing scale.

Her most recent research focuses on techniques that enable a system to continue operating properly in the event of the failure of some of its components. Her work on practical Byzantine fault tolerance demonstrated that there were more efficient ways of dealing with arbitrary (Byzantine) failures than had been previously known. Her insights have helped build robust, fault-tolerant distributed systems that are resistant to errors and hacking. This research is likely to change the way distributed system designers think about providing reliable service on today's modern, vulnerable Internet.

The Turing Award is given annually by the Association for Computing Machinery and is named for British mathematician Alan M. Turing, who helped the Allies crack the Nazi Enigma cipher during World War Two. Professor Liskov will formally receive the award at an ACM gathering on June 27, 2009 in San Diego.