THIS YEAR, I'VE SEEN that there is no shortage of very capable individuals, research institutions, nonprofit organizations, and government agencies working to solve the world's problems. I've also seen that we can be far more effective and see lasting impact if we work together — and work strategically.

The foundation's efforts stem from Bill and Melinda Gates' belief that every life has equal value; no matter where a person lives, he or she should have the chance to lead a healthy life, receive a quality education, and get important information. They also strongly believe that most of the world's major challenges are solvable.

As William H. Gates Sr. recently told a roomful of government, nonprofit, and business leaders, "AIDS will yield. But the end of AIDS will not come from the commitment of one large foundation or even one large government. AIDS will fall to the relentless, persistent attack of millions of people — rich and poor — who decide the time has come for AIDS to go."

Finding — and distributing — an AIDS vaccine. Preparing all of our nation's children for college. Ending homelessness. These goals might seem impossible. But I don't believe they are — if each of us does our part. At the Bill & Melinda Gates Foundation, we feel that our role is to invest in tools and innovative solutions for the world's toughest problems. That's why we're devoting a significant percentage of our resources to building low-cost, life-saving interventions, especially through vaccine research. That's why we're partnering with school districts and experts in education to design innovative schools that truly engage their students.

But even if the foundation funds crucial breakthroughs, we do not have the resources to reach everyone in need. We count on businesses, governments, nonprofit organizations, and volunteers to expand and sustain our grantees' work.