Frances ‘Fran’ Allen

A Pioneer in the

World of Computing

Fran Allen


Frances Elizabeth Allen (August 4, 1932 – August 4, 2020) was a computer scientist and pioneer in the field of optimizing compilers. In 1989, Fran was the first woman to become an IBM Fellow, and in 2006 became the first woman to win the Turing Award. Her achievements include seminal work in compilers, program optimization, and parallelization. She worked for IBM from 1957 to 2002 and subsequently, was a Fellow Emerita, providing technical guidance in her retirement.


Fran Allen Video

Early Life

Growing up near Lake Champlain, N.Y. on a dairy farm, Frances ‘Fran’ Allen was the oldest of six children. On that farm, Fran learned the value of hard work , dedication and humility, and would often read books by kerosene after a day of working on the farm and attending school. In high school, Fran was inspired by her own math teacher and decided to pursue the important vocation herself. 

Like many women of her generation, she attended the New York State College for Teachers (now the State University of New York at Albany) and earned a Bachelor’s degree in mathematics with a minor in physics. Fran taught everything from elementary algebra to advanced trigonometry for two years at the same high school she had attended.

“All the things I do are of a piece. I’m exploring the edges, finding new ways of doing things. It keeps me very, very engaged.”

The Fortran Automatic Coding System for the IBM 704 (15 October 1956), the first programmer's reference manual for Fortran

After two years of teaching, Fran decided to continue her education and pursued her Master's degree in mathematics at the University of Michigan. During her tenure at the university, one of the few institutions teaching computer science in the 1950s, Fran took a handful of basic computing classes. Fran learned that IBM was interviewing potential candidates on campus and signed up for an interview. When offered a position, she envisioned herself working for IBM for just a year, mainly to help pay off her loans from her Master’s degree program and planned to return to teaching—a job that she loved. Fran's first day at IBM Research was on July 15, 1957, just three months prior to IBM’s introduction of FORTRAN (FORmula TRANslation), the first high-level programming language.  

Given Fran’s background in teaching and the need to rapidly train Research division scientists in this new, rather complex language, Fran’s first job at IBM was to teach FORTRAN. Although she initially planned to return to teaching after paying off her student loans, Fran ultimately remained at IBM for the duration of her career.


Throughout Fran’s storied career, she developed a number of breakthrough programming-language compilers In the early 1960s, Fran led a team of researchers that designed one of the first supercomputers, the Stretch Harvest—for the U.S. National Security Agency. The machine could decrypt messages using three different programming languages: FORTRAN, Autocoder, and Alpha.

She also designed and built the machine-independent, language-independent optimizing component of the Experimental Compiler for IBM’s Advanced Computing System. The code helped drive technological improvements of hardware design, and it created a new way to analyze and transform programs. Allen wrote a seminal paper, “Program Optimization,” first published internally at IBM in 1966. It describes a robust new framework for implementing program analysis and optimization as well as a powerful set of new algorithms. 

The Stretch supercomputer —Engineers with Tractor tapes for Harvest

Redundant Subexpression Elimination— This optimization, which is also called common subexpression elimination, involves finding and eliminating those computations which calculate values already available. Consider the following examples in which the redundant subexpression is identified by being enclosed in a box.


Fran’s 1970 paper on Control Flow analysis introduced the notion of “intervals” and node dominance relations, important improvements over the control flow abstractions given in her earlier paper. Fran's 1972 paper which she co-wrote with fellow researcher and collaborator, John Cocke, “A Catalog of Optimizing Transformations”, identified and discussed many of the transformations commonly used today. These papers and her subsequent works, including the first paper on interprocedural analysis, initiated a vast outpouring of algorithms and methods launched by her pioneering projects and papers. 

IBM Research Magazine

Summer 1989

Becoming IBM's
First Female Fellow

Fran became the first woman to become an IBM Fellow, receiving the company’s highest technical distinction in 1989. Fran was not the first woman at IBM Research; in fact, she was one of many. “Later, as computing emerged as a specialized field, employers began to require engineering credentials, which traditionally attracted few women. But the pendulum is swinging back as women enter the field from other areas such as medical informatics, user interfaces and computers in education.”

Turing Award

In 2006, the Association for Computing Machinery named Fran the recipient of the A.M. Turing Award for contributions that fundamentally improved the performance of computer programs in solving problems, and accelerated the use of high performance computing. As significant, it marked the first time a woman had received this honor. The Turing Award is widely considered the "Nobel Prize in Computing." 

Fran’s contributions also extended earlier work in automatic program parallelization, which allows programs to use multiple processors simultaneously in order to obtain faster results. These techniques have made it possible to achieve high performance from computers while programming them in languages suitable to applications. They have contributed to advances in the use of high performance computers for solving problems such as weather forecasting, DNA matching, and national security functions

A passion for adventure
 and mountain climbing

When she wasn’t exploring new computing opportunities, Fran’s passions was seeking adventure, running, and climbing mountains. She was a member of the American Alpine Club and the Alpine Club of Canada, participating in exploratory expeditions to the Artic and on the Chinese/Tibet border. In an interview with author Janet Abbate, Fran reflected on her love for hiking and the mountains, and equated it to her career: “And, you know, it’s somewhat of the same sort of thing: it’s kind of challenging, and interesting; and how does one involve oneself in it? What capabilities does one bring to it that will make a difference?”

Post IBM

Following her retirement from IBM in 2002, Fran served as an IBM Fellow Emerita. A passionate researcher, she continued to be actively involved in the industry and worked closely with professional organizations to increase the role of women in computing. Fran was a member of the American Philosophical Society and the National Academy of Engineers and a Fellow of the American Academy of Arts and Sciences, Association of Computing Machinery, IEEE and the Computer History Museum. She was also bestowed with honorary Sc.D. degrees from several universities.