(Facebook/AP Photo)

Facebook founder and CEO Mark Zuckerberg married Priscilla Chan today, two days after the social networking site had the biggest tech  IPO in history and five days after the bride graduated from medical school.

The wedding was announced, of course, on his Facebook page, along with a photo of the happy couple, and in less than an hour nearly 200,000 people had "liked" the news.

Zuckerberg, 28, and Chan, 27, who met nine years ago at Harvard, married in a small ceremony in the backyard of his home in Palo Alto, Calif. Chan graduated from medical school at the University of California, San Francisco, on Monday, the same day Zuckerberg turned 28.

A guest authorized to speak by the couple said there were fewer than 100 people at the ceremony, and they all thought they were there to celebrate Chan's graduation.

Zuckerberg designed the simple ruby wedding ring himself, and Chan had not seen it before the ceremony, the guest said.

The couple had been planning the ceremony for four or five months, the guest said.

The wedding feast came from the couple's favorite Palo Alto restaurants, Palo Alto Sol and Fuki Sushi, and for dessert they had Burdick Chocolate "mice," which Chan and Zuckerberg had on their first date.