Eich became the CEO of the nonprofit company on 24 March but came under immense pressure after it was revealed he had donated $1,000 for the successful Proposition 8 ballot measure that passed in the November 2008 California state election.
That proposition outlawed gay marriage in California, and Eich had donated to the 'yes' movement, and even though he donated as an individual he listed 'Mozilla Foundation' as his employer.
Eich's appointment as Mozilla Foundation CEO led some of the company's employees to resign or protest, while some members of the wider LGBTI community called for a boycott of Mozilla products and services.
Three of Mozilla's directors resigned, but it's understood they were set to step down from their positions anyway.
Meanwhile online dating destination OKCupid protested by refusing to allow users to run the dating website with the Firefox browser.
A statement from an OKCupid spokesman said that the dating site firm is “pleased that OkCupid’s boycott has brought tremendous awareness to the critical matter of equal rights for all individuals and partnerships; today’s decision reaffirms Mozilla’s commitment to that cause.”
OKCupid said it would end its boycott after "consultation with Mozilla and understanding their commitment to take affirmative action," according to reports.
OKCupid’s management had not called for Eich’s resignation but the company said today, “We are satisfied that Mozilla will be taking a number of further affirmative steps to support the equality of all relationships.”
In a statement on the Mozilla website, executive chairwoman Mitchell Baker said the foundation apologised and that Mozilla let down its community.
"Mozilla prides itself on being held to a different standard and, this past week, we didn’t live up to it. We know why people are hurt and angry, and they are right: it’s because we haven’t stayed true to ourselves.
"Brendan Eich has chosen to step down from his role as CEO. He’s made this decision for Mozilla and our community," Baker wrote. "Mozilla believes both in equality and freedom of speech. Equality is necessary for meaningful speech. And you need free speech to fight for equality. Figuring out how to stand for both at the same time can be hard."
"What’s next for Mozilla’s leadership is still being discussed," she said.