Alexandra Illmer Forsythe is best known for a series of several books on computing and computer science, although she was also a good mathematician and computer programmer in her own right.

Alexandra Illmer Forsythe, or Sandy as she preferred to be known, was born in 1918 and studied mathematics as an undergraduate and then again for her graduate studies. During graduate school she became interested in computing. During the 1950s Forsythe spent a great deal of time trying to get computers into schools in the Palo Alto area where she was living. Forsythe went on to write several textbooks on computers and computer science including, in 1969, the first textbook written on computer science, Computer Science: A First Course. Forsythe's books were written during the 1960s and 1970s, with many of them being produced in numerous editions. Forsythe was very interested in education and she spent time teaching computer science at Utah University, Stanford University (where her husband, George Forsythe, was chairman of the department), and at Cubberley and Gunn high schools in Palo Alto.

When Sandy Forsythe died in 1980 all of her computing notes and the extensive collection of early computing devices she and her husband had collected were bequeathed to Stanford University where they form the Forsythe Archives in the Stanford Library. In honor of the Forsythes, Stanford University holds an annual George and Sandra Forsythe Memorial lecture series.