The richest person in the world is fast becoming the world’s most generous one. Bill Gates made his mark by leading Microsoft, where he met his wife, Melinda. Five years ago, Bill and Melinda Gates took a life turn by deciding to give away much of their fortune through a charity they founded.

How did Bill Gates get so rich? Gates began programming computers at 13. In 1975, he founded Microsoft with a friend. In the 1980s and 1990s, Gates guided Microsoft through important changes with personal computers, e-mail and the Internet. Today, Microsoft is the world’s largest computer software company, and Gates has more than $46 billion.

Bill and Melinda Gates feel that with success comes responsibility. Bill’s mother, who was active in community work, inspired the couple to share their wealth. They co-founded the Bill & Melinda Gates Foundation, providing the charity with billions of dollars. The organization is a leader in the fields of global health and education. It has given scholarships to students and resources to libraries. Now the focus is on cutting-edge medical research and using it to save lives.

In 2005, the Gates Foundation gave more than a billion dollars to improve the health of people in poor countries. The Foundation spends money fighting diseases that get the least attention.

In October, their Foundation pledged to spend $258.3 million to fight malaria, a disease that kills 2,000 African kids every day. Melinda thinks that people are beginning to understand the issue. "If it was their neighbor who was dying of that disease," she told TIME, "they would care a lot." Bill said, "For far too long, malaria has been a forgotten epidemic."

For being champions of global health and for using their wealth to help people around the world who need it most, Bill and Melinda Gates are nominees for TFK People of the Year.