Meet history's most brilliant female coders

From a gifted 19th-century countess to a maverick naval officer, these women blazed a trail for computer programmers today.

This year, another glass ceiling broke when Karen Uhlenbeck became the first woman to win mathematics' prestigious Abel Prize. Her achievement no doubt inspired legions of young girls already passionate about STEM—science, technology, engineering, and mathematics—and served as a salute to the woman mathematicians who came before.

One such woman is NASA mathematician Katherine Johnson, who once said of her love of math, "I counted everything. I counted the steps to the road, the steps up to church, the number of dishes and silverware I washed … anything that could be counted, I did.”

Here, for National Women's History Month, we honor some coding pioneers whose careful calculations led to many of the world's greatest technological advances, from programming the first computers to successfully putting humans on the moon.