Former President Bill Clinton, money guru Suze Orman and Facebook CEO Mark Zuckerberg have weighed in on Apple CEO Tim Cook's coming out.

Cook's sexuality was an open secret. But his acknowledgment on Thursday that he's gay and “proud” makes him the first openly gay CEO of a Fortune 500 company.

(Related: Tim Cook: Being gay “among the greatest gifts God has given me.”)

“From one son of the South and sports fanatic to another, my hat's off to you @Tim_cook,” Clinton tweeted on Thursday.

Appearing on CNN, Orman, who came out in 2007, said that Cook's coming out will help others in corporate America struggling with their sexuality.

“It was a big step for him because it was the one thing he was not hiding but that he felt like he needed to do, at least according to what he wrote, to help all those who may need a little bit encouraging to say, 'It's okay, look, you can do anything you want and still be gay,'” Orman said.

In sharing Cook's essay in a Facebook post, Mark Zuckerberg, Facebook's co-founder and chief executive, wrote: “Thank you Tim for showing what it means to be a real, courageous and authentic leader.”