Female visionaries have always been at the vanguard of innovation, and in fact, women turn up at the very beginning of every important wave in technology. They may have been hidden in plain sight, their inventions and contributions touching our lives in ways we don't even realize, but they have always been part of the story. Here Claire Evans introduces such figures as Ada Lovelace, who wove the first computer program in 1842; Grace Hopper, the tenacious mathematician who democratized computing after World War II; Elizabeth "Jake" Feinler, the one-woman Google who kept the earliest version of the Internet online; and Stacy Horn, the cyberpunk who ran one of the world's earliest social networks out of her apartment in the 1980s.