1. Mosaica Education

Revenue growth from 1999 to 2003 7,695%
Revenue for 2003 84.4 million
Full-time employees in 2003 1,327

New York City

Mosaica operates charter schools in eight states and the District of Columbia. Click here to read the full profile.

2. Intercosmos Media Group

Revenue growth from 1999 to 2003 5,252%
Revenue for 2003 15.2 million
Full-time employees in 2003 59

New Orleans

A group of Louisiana entrepreneurs launched Intercosmos in 1999 to offer free Web hosting. Revenue at first came from advertising; in 2000 Intercosmos was able to start charging for domain names. The company works with the city to employ four public-school interns a year, training them in customer support. Many of those students are later hired full-time.

3. Tech Valley Communications

Revenue growth from 1999 to 2003 4,280%
Revenue for 2003 10.3 million
Full-time employees in 2003 50

Albany, N.Y.

The late-'90s telecom bust actually helped Kevin O'Connor get his phone company off the ground. Trolling on eBay, he found $50,000 routers for $5,000. Tech Valley now uses that equipment to provide phone and high-speed Internet services to a customer base that is mostly commercial.

4. 180s

Revenue growth from 1999 to 2003 3,643%
Revenue for 2003 44.7 million
Full-time employees in 2003 98

Baltimore

Employees at 180s (No. 1 on last year's Inner City 100) not only make ear warmers, gloves, and sunglasses, they mentor freshmen and sophomores at an inner city high school. While the high school's dropout rate hovers at 60%, 99% of the students in the program have gone on to graduate.

5. The Piston Group

Revenue growth from 1999 to 2003 3,107%
Revenue for 2003 227.7 million
Full-time employees in 2003 370

Detroit

Vinnie Johnson started this auto-parts company after a National Basketball Association career. Click here to read the full profile.

6. Global Technology Resources

Revenue growth from 1999 to 2003 2,570%
Revenue for 2003 17.7 million
Full-time employees in 2003 21

Denver

Workers from Lance K. Vierra's computer hardware reseller recently climbed three 14,000-foot peaks to install a wireless communication system meant to help firefighters communicate by radio over a larger geographic area during a wildfire.

7. Peopleclick

Revenue growth from 1999 to 2003 2,538%
Revenue for 2003 42 million
Full-time employees in 2003 273

Raleigh, N.C.

Peopleclick's Web-enabled human resources software helps companies manage the hiring process by, for instance, prescreening applicants and automatically e-mailing rejection notices to unqualified ones. Still, sometimes the best recruiting tools are old-fashioned; one of Peopleclick's big draws, according to CEO Stephen Sasser, is its downtown location.

8. Traf-Tex

Revenue growth from 1999 to 2003 2,115%
Revenue for 2003 7.8 million
Full-time employees in 2003 40

Houston

Mario Reyna knows how to stop traffic. Reyna, an electronics technician turned CEO, estimates that his company has installed 8% of all the traffic signals in greater Houston. Traf-Tex also builds and services surveillance cameras for highways and electronic road signs.

9. Coakley-Tech

Revenue growth from 1999 to 2003 1,950%
Revenue for 2003 10.2 million
Full-time employees in 2003 109

Milwaukee

In the past three years, Coakley-Tech, which helps businesses store files of documents physically and digitally, has gone from three clients to 35, including the health care division of GE and Milwaukee's own Harley-Davidson. New president Chris Illman says cities should focus more on local procurement. "In turn, companies like Coakley-Tech will hire from within the city and everybody wins," he says.

10. Resources for Senior Living

Revenue growth from 1999 to 2003 1,852%
Revenue for 2003 10.8 million
Full-time employees in 2003 525

Charlotte, N.C.

With nine residences in Texas and the Carolinas, Resources for Senior Living caters to seniors who don't need nursing-home care but do need assistance, be it with bathing, eating, or taking medication.