He’s joined a growing list of zillionaires who have decided that, since you can’t take it with you, you might as well give it all away.

From AnnArbor.com:

Tom Monaghan, the founder of Ann Arbor-based Domino’s Pizza who now focuses his time on Catholic philanthropy, is officially pledging to give away at least half his fortune.
Monaghan signed the “Giving Pledge,” a campaign by Microsoft co-founder Bill Gates, his wife Melinda Gates and investor Warren Buffett to convince the nation’s extremely rich people to donate at least half of their wealth to philanthropic causes before or after their deaths.

Monaghan’s net worth today is unclear. BusinessWeek estimated in 2005 that he had $500 million in assets but had already distributed or pledged to give away $451 million.
“I came into the world penniless and as a Catholic Christian, I know that I cannot take any of it with me, so it has long been my desire to use the material resources that I have been blessed with to help others in the most meaningful ways possible,” Monaghan wrote in a letter explaining his pledge.

“I am very grateful not only for the resources that I have been blessed with, but the opportunity to use these resources to help others in the best way I know how.”
Since selling his homegrown global pizza delivery chain in 1998, Monaghan has focused his time almost exclusively on his efforts to spread Catholicism through education. In 2009, his Ave Maria School of Law moved from Ann Arbor to Naples, Fla. to be located near Ave Maria University in Ave Maria, Fla.

Monaghan indicated in his letter that he plans to focus most of his donations on his Catholic education initiatives.

There is much more, including the text of the letter, at the link.