The global force called the Gates Foundation

NEW YORK (FORTUNE Magazine) -- It is by far the largest foundation in the world - even now, before Warren Buffett's historic gifts. And its creed is appropriately broad: "Guided by the belief that every life has equal value, the Bill & Melinda Gates Foundation works to reduce inequities and improve lives around the world."

To further its work, the foundation currently has just over $30 billion in assets, a purse built up from Bill and Melinda Gates' gifts of $26 billion and appreciation in its broadly diversified investments (which at the moment contain no Microsoft).

The $30 billion, of course, does not include the $8 billion in gifts that the foundation has made since 1994. Last year it gave $1.36 billion, and this year it expects to spend around $1.5 billion.

Now it will be Buffett and the Gateses building up the foundation together. Bill and Melinda have said that almost all their fortune will go to charity, and right now they still have an estimated net worth of $50 billion.

The foundation works heavily through partners (nongovernmental organizations, usually) and has focused on big causes. Its original giving was directed at providing U.S. libraries free online access - and today more than 99% are hooked up.

The foundation then broadened its efforts to global health, on which it now spends around 60% of its funds. Much of that is beamed at what Bill Gates calls "the Big Three diseases": malaria, HIV/AIDS, and tuberculosis. The foundation is both pushing to discover a preventive AIDS vaccine and to deliver antiretrovirals to people already afflicted with the disease.

In other areas, spending is focused on making medical "leaps" - the discovery, say, of a chemical that would block malaria-transmitting mosquitoes from smelling humans.

The Pacific Northwest receives sizable Gates grants. The national drive, meanwhile, is riveted on improving high schools, which Bill Gates has called "obsolete." The foundation and its partners have started 900 new schools and "redesigned" 700 others.

The schools effort has stuttered some as the foundation has struggled to find out what works. But CEO Patty Stonesifer says roadblocks only stiffen the foundation's resolve. "We'll be stepping up our investment here," she says, "because providing every student a quality education is key to ensuring equality of opportunity."

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