Facebook CEO Mark Zuckerberg is officially a dad!

"Priscilla and I are so happy to welcome our daughter Max into this world," Zuckerberg posted on his Facebook page. 

To celebrate her birth, he and wife Priscilla Chan plan to donate 99% of their Facebook shares--about $45 billion--to "advancing human potential and promoting equality" through a new organization called the Chan Zuckerberg Initiative. 

Zuckerberg will still retain majority voting rights in Facebook.

The new company will fund non-profits and focus initially on personalized learning, curing disease, connecting people, and building strong communities. 

Here's Zuckerberg's full post, including a letter that he and Chan wrote their daughter about the world they hope she grows up in: