Mark Zuckerberg and his wife Dr Priscilla Chan have revealed they welcomed a baby daughter last week.
The Facebook founder and his wife have penned a very sweet open letter to their baby girl, called Max, on the site revealing another HUGE announcement.
The couple wrote: "Max, we love you and feel a great responsibility to leave the world a better place for you and all children. We wish you a life filled with the same love, hope and joy you give us. We can't wait to see what you bring to this world."
Your mother and I don't yet have the words to describe the hope you give us for the future. Your new life is full of promise, and we hope you will be happy and healthy so you can explore it fully. You've already given us a reason to reflect on the world we hope you live in.Like all parents, we want you to grow up in a world better than ours today.
They then pledged to donate 99% of their Facebook shares - worth about $45 billion - during the course of their lives to “promote equality and the human potential.”
Zuckerberg and Chan met while they were both students at Harvard. They announced their pregnancy back in July, revealing they'd suffered miscarriages in the past.
Congratulations Mark and Priscilla! And welcome to the world Max!