Answer: Ada

Augusta Ada King—born Augusta Ada Byron, later known as Ada Lovelace after becoming the Countess of Lovelace when her husband William King became the Earl of Lovelace—is best known for her work on Charles Babbage’s analytical engines.

Her surviving notes regarding work on the engines include what is recognized as the first algorithm designed to be carried out by a machine and, as such, she is considered the world’s first computer programmer. Although her algorithms were not implemented within her lifetime, they are significant in that they predicted a time in which computers would perform tasks beyond simple calculations and number-crunching—her contemporaries, including Babbage himself, remained fixated on the actual construction of the machines and the calculations and number-crunching that would follow.

Over a century after her death, programmers honored her role as the world’s first programmer by christening a new programming language after her. Ada, an object-oriented high-level computer programming language, was created in the late 1970s under contract from the United States Department of Defense. The goal was to replace the hundreds of diverse and incompatible languages used across the Department, many of which were quickly becoming obsolete and were too hardware-dependent.

To that end, the Ada project was wildly successful, so much so that by 1991, the Department of Defense began to require the use of Ada (The Ada Mandate) for all software, though exceptions to this rule were often granted. Ada reigned supreme until 1997 when the Department of Defense shifted towards a higher utilization of off-the-shelf technology (including programming languages).

Although it is no longer a mandated Department of Defense programming language, Ada still enjoys widespread popularity both inside and outside of the Department thanks to excellent stability and security features. The language is frequently used in mission/safety-critical applications where reprogramming isn’t an option or failure would yield costly or catastrophic results. Current applications for Ada include commercial rocket, air traffic control, satellite control, railway control, and banking infrastructure systems.