Today was Ada Lovelace Day, a day for commemorating women's contribution to science and technology, named after the woman who is widely credited as being the world's first computer programmer.

Augusta Ada King, the Countess of Lovelace and daughter of Lord Byron, was an English writer who collaborated with British mathematician Charles Babbage on notes about his Analytical Engine – a steam-powered mechanical computer.

The engine was never built in Babbage's or Lovelace's lifetimes, but a project is now underway in the UK, headed by British programmer and blogger John Graham-Cumming, to build a working model.

Lovelace translated an article by Italian mathematician Luigi Menabrea on the engine for Babbage, and added extensive notes on it, including an algorithm for the steampunk machine that many consider to be the first computer program – a method for calculating a sequence of Bernoulli numbers with the contraption.

There is some debate about how much of her notes were her own work and how much was at Babbage's direction, but she has nevertheless had a computer language named after her and had a medal from the British Computer society awarded in her name in 1998. She was also played by Tilda Swinton in the 1997 film Conceiving Ada.

The idea of having a day named after Lovelace is more about recognising women in maths, science and technology than the lady herself, though.

The Twitterati has marked the day with shout-outs to women, such as this list of female tweeters involved in the tech, science, environment or health world, and the website findingada.com has been urging readers to tell their stories about women in the sciences who have inspired them. ®