Open source programs run the world, from mobile apps and bitcoin to tangible products like Amazon Echo and Toyota cars. But men dominate the open source community, where supposedly anyone can contribute code.

“My female friends and I are still being insulted, harassed, and groped at open source conferences,” programmer Valerie Aurora wrote on the free software community LWN.net. Online forums are equally hostile.

A new survey of 6,000 GitHub users, a platform described by Wired as the world’s leading hub of open-source code, just showed open source has an ever bigger diversity problem than the tech industry at-large. And that bar was already pretty low.

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According to a study of American tech companies by the Anita Borg Institute, women on average held 21.7 percent of tech jobs. The disparity is pretty similar in management roles and university engineering programs, Bloomberg reported. Although women make up a small fraction of the open source community, just 3 percent of survey respondents, female coders are more likely to receive unsolicited sexual advances and "language or content" that made them feel unwelcome, 25 percent versus just 15 percent of male programmers.

Such negative behavior can range from rude criticism and insults to online harassment like doxxing and stalking. Overall, 21 percent of respondents who witnessed or experienced negative behavior on stopped contributing to an open source project because of it.

Half of the GitHub survey respondents said their open source work helped build their professional reputations and get their current jobs, which suggests that sexist critiques in the male-dominated open source culture could hurt women's career prospects. Sexism curtails great code and excludes talented programmers across the board. An older study by Emerson Murphy-Hill, based on  GitHub’s 2016 data, proved women’s code was statistically rated better than men’s if female programmers disguised their gender with a unisex name.

Jigyasa Grover, Director of the Women Who Code Delhi Network, told International Business Times she keeps a low profile on GitHub because she’s heard about users with feminine names receiving harsher criticism. “Women especially find it intimidating to get started with contributing to open source,” Grover said. “Github means openly showcasing your code. It takes a great deal of confidence to contribute to open source, which might be more difficult for female developers to overcome, given the tech industry’s poor history with welcoming women.”

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Patronizing language and constant scrutiny take a toll on women programmers. The discrimination women face can often lead to career burnout.  A global survey of chief information officers (CIOs) found women make up only nine percent of senior IT leadership roles in the tech industry. “Many females tend to leave tech roles by mid-career,” Grover explained. “There is just an unconscious bias which complicates the issue further.” The Wall Street Journal reported Facebook rejected code from female engineers 35 percent more than code from male counterparts.

Despite the challenges, Grover said there are steps techies can take to empower women in open source communities. Tech companies can invest in community management and weed out harassment, prioritize diverse hiring and promotion policies, while leveraging parental leave and company-wide diversity training to help older women move up the career ladder. According to Quartz, when Google increased paid maternity leave the number of new moms who quit dropped by 50 percent.

Correction: This story was updated to reflect the survey was not just about Github but open source broadly. A 2016 study about code written by women being "statistically rated better" than men was from an Emerson Murphy Hill paper using scraped data from GitHub, not a study from Github itself.