The effects of Northern Virginia’s federally fueled growth are evident in the latest Fantastic 50, our annual list of the 50 fastest-growing, privately held companies in Virginia.

More than half of the companies on the list, 28, are based in Northern Virginia and many of them have benefited from government contracts. In fact, nine of the top 15 companies are from the region. By comparison, 24 companies from Northern Virginia made last year’s list. The Hampton Roads region claims 12 companies on the 2005 list, down from 14 last year.

Northern Virginia is undisputedly the state’s economic engine. In recent years, its growth rate has outpaced the state’s, and the region’s unemployment is consistently the lowest in Virginia. Since the 9/11 terrorist attacks, much of the growth has come from increased spending for defense and homeland security.

Five companies from the Fantastic 50 are profiled in the following pages. They are THR Enterprises Inc. of Norfolk, the company with the highest overall growth for the second year in a row; Strategic Business Systems Inc. of Herndon, the service company honoree; Intelligence Data Systems Inc. of Reston, the technology leader; AVID Medical Inc. of Toano, the top manufacturing company; and Premier Pet Products LLC of Richmond, the leader among wholesale/retail firms.

Now in its 10th year, the Fantastic 50 honors privately held, Virginia-based companies with the highest revenue growth over a four-year period. The Virginia Chamber of Commerce started the recognition program. To be eligible for the list, a company must have revenue of at least $200,000 in 2000, the base year. In addition, the company must have a positive net income by 2003 and have revenue of less than $100 million in its most recent year.