Women's many contributions to technology are frequently left out of the history books. But lately, that's been changing — at least a little. Ada Lovelace, considered the first computer programmer and a visionary for what programming and computers could eventually become, has a technology award named after her, and a holiday devoted to celebrating her legacy. Katherine Johnson meanwhile, the NASA "computer" responsible for successfully plotting the flight paths of some of America's earliest space exploration expeditions, was the subject of the Hollywood blockbuster Hidden Figures (and the book it's based on).

But the stories of far too many of the women who drove innovation in the 19th, 20th, and into the 21st centuries — these key technological architects of modern life — have long gone unheard, their praises unsung. Here are a few of the 15 great ladies of technology you really need to know about:

  •  Williamina Fleming and the Harvard "Computers"
  • The 'mother of computing': Grace Hopper
  • The woman you have to thank for hybrid car batteries: Annie Easley
  • 'Google-ing' something would never have occurred to men without her: Karen Spärck Jones

Read about all of the unsung women in tech by Rachel Kraus at Mashable.