Augusta Ada King, Countess of Lovelace(1815-1858), amateur mathematician and close friend of Charles Babbage, wrote the first significant computer program to create instructions for the Analytical Engine. This program featured several of the concepts used in today's computer programming, such as the loop. The ideas of Babbage and Lady Ada were forgotten after their deaths until one of the first real computers was built, about 100 years later.

Charles Babbage(1791-1871), English mathematics professor and inventor, sought to produce error-free mathematical tables. Babbage noticed that machines excelled at doing repetitive tasks without error, and the production of mathematical tables often required the simple repetition of steps. His first attempt at applying the abilities of a machine to mathematics was called the Difference Engine (1842), designed to perform differential equations. Later, Babbage designed a more general machine, the Analytical Engine, to do a variety of calculations. Although his designs were basically sound, the technology at the time was not available to manufacture the mechanism. Even though it was never completed, it had many of the features of a today's computers:

1. input/output devices
2. a calculating unit
3. a control unit
4. a storage for numbers to be processed

The ideas of Babbage and Lady Ada were forgotten after their deaths until one of the first real computers was built, about 100 years later.

Grace Murray Hopper was one of the leading pioneer figures in computing. Born in 1906, she earned a Ph.D. degree in mathematics from Yale in 1934, a truly remarkable achievement for a woman at that time. During World War II, Dr. Hopper joined the United States Naval Reserve. Her committment to the Navy continued for many years; she retired from the Navy with the rank of Rear Admiral.

During the war, Dr. Hopper worked at Harvard on the Mark I computer. A computer folktale asserts that the term "bug", meaning an error in a program, stemmed from her account of finding a dead moth stuck in the mechanical relays of that early computer.

She believed that the key to opening up widespread use of the new and complex computing devices of the 1950s lay with programming languages that used English commands rather than cryptic statements that only the computer could easily understand. She campaigned among business leaders for acceptance and use of the COBOL business programming language. In 1969, the Data Processing Management Association awarded her its first Computer Science Man-of-the-Year Award. Throughout her career, she gave many public lectures in a stimulating manner that helped nontechnical people understand the nature of computers and computing.

Active and working well into her 80s, Rear Admiral Grace Murray Hopper died on January 1, 1992.

Lee de Forest invented the triode vacuum tube in 1906. This device provided amplification for radio, telegraphy, and telephony. More on Lee de Forest

John von Neumann(1903-1957) A brilliant mathematician who developed the stored program concept. His idea was to store not only the data to be processed in computer memory, but also the instructions used to process the data. He designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 to hold a stored program.

Alan Turing(1912-1954) One of the most celebrated computer scientists, is famous for his three major contributions to the science:

1. the first mathematically sophisticated theory on computation (Church-Turing Thesis), including some profound and astonishing discoveries about machine capabilities (the universal Turing machine)
2. an active participant in the construction of the secret code-breaking British Colossus
3. the Turing "intelligence test", a method to determine if a computer possesses intelligence

Daniel Bricklin, as a Harvard business student, along with Robert Frankston and Dan Fylstra developed the first electronic spreadsheet program, VisiCalc, in 1979.