PHILADELPHIA -- Dennis Ritchie and Kenneth Thompson, the world-renowned computer scientists who invented the UNIX operating system at Bell Labs in 1969, are the recipients of this year's Harold Pender Award, the highest honor bestowed by the University of Pennsylvania's School of Engineering and Applied Science.  A Nov. 12 lecture, reception and awards dinner at Penn will honor their pioneering accomplishments in the development of the UNIX operating system and the C programming language.

Initiated in 1972, the Pender Award is given by faculty in Penn's Moore School of Electrical Engineering to an engineer who has made significant contributions to society.  Past recipients have included Jack St. Clair Kilby (2000), for contributions to the invention of the microchip; Bell Labs scientist Arno Penzias (1991), who discovered, with Robert Wilson, the faint background radiation remaining from the Big Bang; Edwin H. Land (1979), inventor of instant photography; and John Mauchly and J. Presper Eckert (1973), inventors of ENIAC, the world's first large-scale, all-electronic, general-purpose digital computer.

Thompson joined Bell Labs' Computing Sciences Research Center in 1966, followed a year later by Ritchie.  The two soon began working together on the creation of the UNIX computer operating system, which among other things lets a number of programmers access a computer at the same time, sharing its resources.  UNIX also employs a client/server model, which helped reshape computing around networks rather than around individual computers, an approach that gave rise to the Internet of today.  

With its unique combination of conceptual economy and portability, UNIX also revolutionized how operating systems are developed.  Although the early distributions were not "open source" in modern terms, they were widely licensed, particularly in the academic and research communities.  As a result, generations of computer scientists contributed to its evolution, and several renditions of its ideas have emerged in open-source form over the last decade.  

UNIX's continuing popularity derives from many factors, including its ability to run on a wide variety of machines, from micros to supercomputers, as well as its inherent reliability.  As a result, UNIX continues to be the operating system of choice for mission-critical computing applications and services.

In 1970 Thompson wrote the B computer language, followed two years later by Ritchie's creation of the familiar C language.  Today, Ritchie continues to do operating system software research at Bell Labs, the research-and-development arm of Lucent Technologies, while Thompson, who retired from the Labs in December 2000, is currently a fellow at Entrisphere, a software startup in California.

Ritchie and Thompson have received several other prestigious awards for their pioneering work, including the National Medal of Technology, which was presented to them by President Clinton in 1998, and the Turing Award from the Association of Computing Machinery in 1983.  Both men have also been elected to the National Academy of Engineering.   

The Harold Pender Award is named for the late founding dean of Penn's Moore School of Electrical Engineering.  Under Pender's direction, the Moore School constructed a differential analyzer for use in solving problems in power and ballistics, leading to the 1946 development of ENIAC.

Pender's own distinguished research career involved basic experimental studies of electric and magnetic fields and applied research in electrical power, a significant societal problem at the turn of the century.  His early research on the relationship of electric circuits to magnetic fields demonstrated quantitatively for the first time that a moving electrical charge produces a magnetic field.

NOTE:  UNIX is a registered trademark of The Open Group.