Perhaps the key component in the economic life of Pittsburgh is a nonprofit -- the colossal University of Pittsburgh Medical Center.

	Graphic: Top Foundations by Size

With 40,000 people, it is a bigger local employer than an array of for-profit enterprises, from U.S. Steel to H.J. Heinz to Mellon Financial to Giant Eagle. The only company with more workers statewide is Wal-Mart, the nation's largest private employer, and the medical center shows no signs of slowing down its expansion, with revenues up 13 percent last year to $5.1 billion and its 19 hospitals considered some of the most profitable in Pennsylvania.

As UPMC illustrates, the real power in Pittsburgh can be found in its nonprofit sector, home to hospitals and foundations and universities and cultural organizations.

	Graphic: Top Colleges

Collectively, they work to improve the quality of life for people in southwestern Pennsylvania and provide venues for learning and questioning the world as it was and is, whether the subject is history, classical music or the art of Andy Warhol. They also attract tens of thousands of visitors from around the world every year and give the area prestige. Perhaps most importantly, the nonprofits are gigantic engines of money and innovation that serve as the primary hope for Pittsburgh's future economic growth.

The nonprofit with the largest revenues in the Pittsburgh area is Highmark Inc., the insurer that collected $9.8 billion in 2005, up 10 percent from 2004. It employs more than 12,000 people.

	Graphic: Top Healthcare Companies

The largest of the nonprofit educators is the University of Pittsburgh, which employs 12,000 and has an operating budget of $1.5 billion. Every year the university attracts 34,000 students from all 50 states and more than 100 counties, including China, Taiwan, India, South Korea and Japan. Considering what Pitt pays its faculty and staff, what it spends on construction, office supplies and food, the university's annual contribution to the local economy is estimated at $1.3 billion.

Pitt's Oakland neighbor is Carnegie Mellon University, second-largest in the area and a draw for almost 10,000 students a year, many lured by CMU's record of innovation and research in such fields as computer science and robotics.

Few nonprofits are quieter about their influence than the region's largest foundations, which as a group handed out $332.7 million in grants last year, an amount within $70 million of the city of Pittsburgh's budget last year.

	Graphic: Top Arts Organizations by Size

Some, such as the McCune Foundation, even ask grant recipients not to disclose the source of the funding. One of the quietest-- and the largest -- is the Richard King Mellon Foundation, which handed out more than $82 million last year. Because of Mellon, the Heinz Endowments (overseen by Teresa Heinz Kerry) and the Pittsburgh Foundation, Pittsburgh has more foundation dollars than other cities of the same size, and the money funds everything from economic development efforts to education to social services to conservation.

The Pittsburgh's cultural scene is another source of nonprofit power. More than 1 million people a year visit local museums, theaters, music halls, parks and historical markers. Fostering much of that creativity and activity are groups such as the Carnegie Museums, the Pittsburgh Cultural Trust, the Pittsburgh Parks Conservancy (builder of a $10 million park in the heart of Oakland set to open this summer), the Mattress Factory, Pittsburgh History & Landmarks and the Phipps Conservatory.

The 26 largest, as measured by 2005 operating budgets, collectively spent more than $260 million last year, allowing people from Pittsburgh and around the world to explore their creative side and perhaps think about life in new ways.