Ada Lovelace: First computer program

In 1842 Charles Babbage was invited to give a seminar at the University of Turin about his analytical engine. Luigi Menabrea, a young Italian engineer, and future Prime Minister of Italy, wrote up Babbage's lecture in French, and this transcript was subsequently published in the Bibliothèque universelle de Genève in October 1842.
Babbage asked Ada to translate Menabrea's paper into English, subsequently requesting that she augment the notes she had added to the translation. Ada spent most of a year doing this. These notes, which are more extensive than Menabrea's paper, were then published in The Ladies' Diary and Taylor's Scientific Memoirs under the initialism "AAL".
In 1953, over one hundred years after her death, Ada's notes on Babbage's Analytical Engine were republished. The engine has now been recognised as an early model for a computer and Ada's notes as a description of a computer and software.

The "Note G" source code: Tabular representation of one of the first 'computer programs', a computation of Bernoulli numbers for the Analytical Engine.

Ada's notes were labelled alphabetically from A to G. In note G, she describes an algorithm for the analytical engine to compute Bernoulli numbers. It is considered the first algorithm ever specifically tailored for implementation on a computer, and for this reason Ada is often cited as the first computer programmer; however, the engine was not completed during Lovelace's lifetime.