It's shaping up to be a big week for public letters.
"Like all parents, we want you to grow up in a world better than ours today," Zuckerberg wrote in the 2,220-word letter, co-written with his wife,
Zuckerberg and Chan also pledged to donate 99% of their Facebook shares -- currently worth about $45 billion -- "during our lives to advance this mission."
They were vague on how and when they would distribute their money, saying they would share more details in the coming months after they returned from their paternity and maternity leaves.
"As you begin the next generation of the Chan Zuckerberg family, we also begin the Chan Zuckerberg Initiative to join people across the world to advance human potential and promote equality for all children in the next generation," the letter said."Our initial areas of focus will be personalized learning, curing disease, connecting people and building strong communities."
In the social media world, Zuckerberg's letter quickly received praise and also some criticism from those who thought he was using his daughter's birth to promote his beliefs.
Dear Max, get ready for a childhood full of dadsplaining.