Women have played a vital role in the advancement of tech over the century. Nevertheless, they remain marginalized, underrepresented, and underpaid in STEM sectors today. In this article, we look at five inspirational women who were pioneers in the tech industry.

1. Hedy Lamarr

Born Hedwig Eva Maria Kiesler in 1915, Hedy Lamarr was a highly successful Austrian actor. She shot to fame as a leading lady in the 1920s starring alongside actors such as Lana Turner, Judy Garland, and Clarke Gable.

Away from the screen, she had another passion: inventing. Although she had no formal training, Hedy Lamarr came up with several inventions, including a tablet that dissolved in water, creating a fizzy drink, and a new and improved traffic light system. Aviation tycoon Howard Hughes recognized Lamarr’s talent, lending her a team of engineers.

Hedy Lamarr’s greatest breakthrough came during World War II. Discovering that radio-controlled torpedoes could be knocked off course, Lamarr invented and patented a frequency-hopping signal that proved impossible to hack. Although her invention was not adopted by the US military until the Cuban Missile Crisis in 1962, Lamarr’s concept proved transferable to a variety of different platforms, including early versions of Bluetooth and Wi-Fi.

2. Manal al-Sharif

Manal al-Shariff was named by TIME Magazine as one of the Top 100 Most Influential People in the World. She is also cited by Newsweek as one of the Top 10 Tech Revolutionaries. A prominent voice for women’s empowerment and rights, she was the first Saudi woman to specialize in Information Security.

Manal al-Sharif’s career started in 2002, when she joined the world’s largest oil company, Saudi Aramco, where she worked as an Information Security Consultant. Today, Manal al-Sharif is a public speaker, columnist, and author, who is perhaps best known for her bestselling memoir, Daring to Drive: A Saudi Woman’s Awakening.

Manal al-Sharif co-founded the #Women2Drive movement which challenged the ban on women drivers in Saudi Arabia. Al-Sharif was subsequently arrested by Saudi police for “driving while female.” She was released on condition of never driving in the country again; never speaking of her arrest; and never giving interviews on the subject.

Following her release, al-Sharif continued campaigning for #Women2Drive regardless. She also established the #IAmMyOwnGuardian campaign, calling for an end to Saudi Arabia’s male guardianship system. Today, Manal al-Sharif is a speaker at Harvard, TED, the United Nations, Google, WIRED, UNESCO, the Obama Summit, the Arab Institute in Paris, Women in the World, and many others.

3. Susan Kare

Referred to as “the Betsy Ross of the Personal computer,” Susan Kare is an interface guru. Using graphic design skills and sophisticated typography, she helped bring the Apple computer to life.

Working alongside Steve Jobs, Susan Kare shaped many interface elements of the Apple Mac. This includes the command icon, which Kare found while skimming through a book of symbols. She is also behind Apple’s Happy Mac icon that greeted users as they booted up their machines, as well as the trash can icon.

Susan Kare’s input was instrumental in making devices feel more personable and less like a machine. In addition to working with Apple, Kare also worked with the Microsoft Corporation, applying her design skills to humanize the Windows 3.0 operating system.

4. Kim Swift                                            

A well-known games designer, Kim Swift is best known for her work at Valve, a video game developer and distributor. While at the company, she designed Portal, a multi award-winning puzzle-platform game as well as Left 4 Dead.

Women had a particularly tough time in the video games industry during the Gamergate controversy, which saw Zoe Quinn, Brianna Wu, and other female games designers subjected to torrents of sexist online abuse. As a result of Gamergate, the sector has stepped up to provide an inclusive environment for women, as well as trans and non-gender binary professionals.

Kim Swift has been featured by Fortune as one of the 30 Under 30 influential figures in the gaming industry. She was also listed as one of the most-recognized women in the sector by Mental Floss.

5. Anne-Marie Imafidon

Imafidon is the founder of social media enterprise, Stemettes, an organization dedicated to promoting women in STEM careers. Born in the United Kingdom in 1990, she was a child prodigy in mathematics, computing, and languages.

She was the country’s youngest-ever Master’s degree recipient, earning the degree when she was only 19. Imafidon received honorary doctorates from the Glasgow Caledonian University and the Open University. She is also an honorary fellow of Keble College, Oxford.

According to a survey by the UK organization WISE, women represent just 24 percent of the UK STEM workforce today. Since its inception, Stemettes has supported nearly 40,000 young people throughout Europe, advancing Anne-Marie Imafidon’s objective of making STEM industries more inclusive and diverse.