GitHub co-founder Tom Preston-Werner has resigned from the company after allegations of sexism and harassment made by former developer Julie Ann Horvath.

The company launched what it called a "full, independent, third-party investigation," which "found no evidence to support the claims against Tom and his wife of sexual or gender-based harassment or retaliation, or of a sexist or hostile work environment," GitHub CEO and co-founder Chris Wanstrath wrote today.

Despite not corroborating the main allegations, "the investigator did find evidence of mistakes and errors of judgment. In light of these findings, Tom has submitted his resignation, which the company has accepted. Tom has been a huge part of this company from the very beginning and we appreciate all that he has done for GitHub. We wish him the best in his next endeavour."

Horvath was a designer and front-end developer for GitHub who also created the company's Passion Projects initiative for women in technology. Horvath left GitHub last month, saying she was "harassed by 'leadership' at GitHub for two years." Horvath said the harassment came from a co-founder and his wife, although she did not name them. Horvath also said a co-worker who was angry that she did not want to date him "started passive-aggressively ripping out my code from projects we had worked on together."

Horvath did not reply to an e-mail from Ars, but she sent out a number of tweets criticizing her former employer:

Horvath further claimed that "there was no investigation... There was a series of conversations with a 'mediator' who sought to relieve GitHub of any legal responsibility."

When asked for a copy of the investigator's report, a GitHub spokesperson told Ars, "the specifics of the investigation are confidential. Everything we're sharing is in Chris's blog post."

"Women at GitHub who sprang forward to defend the men who harassed me, it is naive to think the same thing cannot and will not happen to you," Horvath wrote on Twitter. "Best of luck rolling the dice."

Preston-Werner is “prepared to fight any further false claims”

Valleywag reported last month that Horvath wasn't the first employee to clash with Theresa Preston-Werner, the co-founder's wife. But other employees said bad behavior in the office isn't universal.

"Several female GitHub employees, who spoke... on condition of anonymity, said they’ve never felt gender discrimination at the company," The Verge wrote. "'I don’t feel isolated or alone,' one female developer says. 'I have never personally experienced anything like that and I’ve never witnessed it.'"

Preston-Werner was immediately placed on leave after the accusations and his wife was banned from the office. GitHub clarified that Theresa Preston-Werner "has never had hiring or firing power at GitHub and will no longer be permitted in the office."

Tom Preston-Werner wrote a post today defending himself and his wife.

"Neither my wife, Theresa, nor I have ever engaged in gender-based harassment or discrimination. The results of GitHub's independent investigation unequivocally confirm this and we are prepared to fight any further false claims on this matter to the full extent of the law," he wrote.

He also wrote, "I've made mistakes, and I am deeply sorry to anyone who was hurt by those mistakes. It devastates me to know that I missed the mark, and I will strive to do better, every day."

Theresa Preston-Werner wrote an article saying, "As expected, we were fully cleared of all accusations of harassment. Still, there is no way to repair the indelible marring of our reputations caused by these allegations and other completely unfounded rumors that were intentionally and maliciously spread about me and my family."

Theresa Preston-Werner's article provided a fleeting view into the GitHub investigation:

I have never known anyone like Tom. When I was interviewed by the 3rd party investigator, she abruptly asked if I thought Tom was naive. I was dumbfounded, unable to answer until she offered a different word; “Perhaps, you would call him optimistic?” Naive, no. Optimistic, absolutely.

Both husband and wife used their posts to tell readers about Theresa Preston-Werner's new startup Omakase, which plans to help raise donations for technology-driven nonprofit organizations.

Wanstrath acknowledged at the time of Horvath's allegations that GitHub had to improve its human resources practices and wrote, "I would like to personally apologize to Julie. It’s certain that there were things we could have done differently."

Today Wanstrath wrote, "We want to create a great place to work for all our employees and we can’t do that without acknowledging the challenges that exist in providing an inclusive work environment. We are implementing a number of new HR and employee-led initiatives as well as training opportunities to make sure employee concerns and conflicts are taken seriously and dealt with appropriately. We know we still have work to do."