We already knew Mark Zuckerberg was a massive giver—the Facebook CEO dropped a $75 million donation on the San Francisco General Hospital this year in addition to setting up a $5 million scholarship fund for undocumented immigrants—but even we were surprised by his most recent announcement.

Zuckerberg and his wife, Priscilla Chan, welcomed their baby daughter Max to the world last week, and in a letter to their newborn, the new parents vowed to donate 99% of their Facebook shares to charity. This reportedly $45 billion sum (enough to buy 9 billion mosquito nets or put 38 billion children through primary school) will be doled out over the course of their lives and will be one of the most charitable donations to date, competing with the likes of mega-giver Bill Gates.

In fact, when Gates caught wind of this news he praised the couple saying, "Max and every child will now grow up in a better world." Zuckerberg confirmed in his letter that it was baby Max that make him come to this decision, saying, “Having this child has made us think about all the things that should be improved in the world for her whole generation.”

The budding organization is known as the Chan Zuckerberg Initiative, with a mission to promote education, combat disease, and strengthen communities.