Stephen Shankland/CNET

Mozilla's new Chief Executive Officer Brendan Eich has resigned, after being dogged by calls for his ouster over his support for an anti-gay marriage bill in California.

Mozilla's board chairman Mitchell Baker announced Eich's resignation in a blog post on Thursday.

"Brendan Eich has chosen to step down from his role as CEO. He's made this decision for Mozilla and our community," Baker wrote.

Eich later confirmed the news in his own prepared statement.

"I have decided to resign as CEO effective today, and leave Mozilla. Our mission is bigger than any one of us, and under the present circumstances, I cannot be an effective leader. I will be taking time before I decide what to do next."

Eich had refused to give up the post, despite a growing chorus of voices demanding his resignation. He was named chief executive of the nonprofit Mozilla Foundation two weeks ago. Mozilla, which Eich co-founded, advocates for an open, inclusive Internet and builds the Firefox Web browser.

"It may be challenging for a CEO, but everyone in our community can have different beliefs about all sorts of things that may be in conflict," Eich said earlier this week, in his first interview about the controversy with CNET's Stephen Shankland.

"Mozilla believes both in equality and freedom of speech. Equality is necessary for meaningful speech," Baker said. "And you need free speech to fight for equality. Figuring out how to stand for both at the same time can be hard."

Eich co-founded Mozilla in 1998 and served as the group's chief technology officer for nearly a decade before being named CEO. But his ascension to the head of the group, which oversees the third-most popular Internet browser, had been challenged after reports revealed he had donated $1,000 to support California's Proposition 8 in 2008. He is the only Mozilla employee on record to have donated to support Prop. 8, although several gave against it. The anti-gay marriage bill rescinded the right for gay couples to marry until it was overturned last year.

More than one Mozilla employee publicly called for his resignation on Twitter, and prominent app developer Rarebit detailed in two blog posts why they were withdrawing support from Firefox OS. "We thought that last week Mozilla would immediately come out with a statement of support of equality and Brendan would issue an apology," Hampton Catlin of Rarebit said in an email to CNET. "Unfortunately, this has become a far larger issue and I'm not sure there is a solution that would please everyone."

Dating site OKCupid took an aggressive stance against Eich, blocking Firefox users from directly accessing the site by forcing them to see a letter of protest written by OKCupid co-founder Christian Rudder on Monday. Yesterday, OKCupid unblocked Firefox without comment.

Eich's future role at Mozilla remains unclear. He has been an influential developer for the Web and is the creator of JavaScript, the coding language that powers many Web sites and mobile apps.

Mozilla did not immediately respond to a request for comment, although Baker did say that the company wants "to be open about where we are in deciding the future of the organization" and promised further details next week.

The Electronic Frontier Foundation, a digital rights nonprofit that has partnered with Mozilla on open Internet efforts, issued a statement in light of Eich's departure, reiterating its support for the organization: "We believe that what Mozilla stands for--building and supporting an open Internet that gives users freedom to communicate, innovate, and stay safe and secure--is a job that few other institutions are in a place to pursue. So as this change occurs, and the discussion continues, we also want to keep our focus on the goal that everyone can agree on: preserving an open Internet."

Updated at 2:45 p.m. PT with a statement from Eich and at 3:15 p.m. PT with a statement from EFF.