In a public post on Facebook, CEO Mark Zuckerberg and his wife Priscilla Chan announced Tuesday that they will donate 99 percent of their Facebook shares "during their lives"—an amount currently worth $45 billion—to their new charity, the Chan Zuckerberg Initiative.

The organization, which seems to be modeled on the Gates Foundation, states its laudable albeit vague goal to “join people across the world to advance human potential and promote equality for all children in the next generation.”

The announcement came in the form of a public letter to their newly born daughter Max. It addresses important long-term goals that are often stymied in the public sector, things like “advancing human potential and promoting equality.”

Zuckerberg and Chan wrote:

Advancing human potential is about pushing the boundaries on how great a human life can be. Can you learn and experience 100 times more than we do today? … Promoting equality is about making sure everyone has access to these opportunities -- regardless of the nation, families or circumstances they are born into. Our society must do this not only for justice or charity, but for the greatness of human progress. Today we are robbed of the potential so many have to offer. The only way to achieve our full potential is to channel the talents, ideas and contributions of every person in the world.

UPDATE 10:56pm ET: A filing with the Securities and Exchange Commission, first reported by BuzzFeed, reveals that the Chan Zuckerberg Initiative is actually organized as a Delaware-based limited liability corporation (LLC), rather than a traditional non-profit.

Facebook did not immediately explain to Ars why its CEO chose this route.

UPDATE #2 Wednesday 6:34pm ET: Lawrence Hamermesh, a business law professor at the Widener University Delaware Law School e-mailed us to clarify that incorporating an LLC for charitable purposes is allowed under state law.

"Section 18-106 of Delaware's Limited Liability Company Act provides that 'a limited liability company may carry on any lawful business, purpose or activity, whether or not for profit, with the exception of the business of banking as defined in § 126 of Title 8,' he wrote. "I take the 'whether or not for profit' phrase to permit a flexible definition of the purpose of the LLC, including pursuit of charitable activity."