Why it's hot:
Red Hat fended off invasions of the Linux market by Microsoft and Oracle, adding 42,000 new customers, including Priceline.com and the FAA.
To find the B2 100, we screened more than 2,000 tech companies that have been publicly traded on a U.S. stock exchange for at least three years, have a market capitalization of at least $50 million, and have had positive operating cash flow over the past 12 months. Zacks Investment Research of Chicago ranked the resulting list using four financial criteria: growth in revenue, profit, and operating cash flow during the past three years, and the 12-month stock return as of Dec. 31, 2006. Cash flow growth counts for 40 percent of a company's ranking. Each of the other criteria counts for 20 percent. Additional research was provided by Factset. If you have further questions about Business 2.0's 100 Fastest growing technology companies, please e-mail talkback@business2.com.