MITRE

US employees: 6,037
Last year's worldwide job growth: 5 percent
Most common job/Avg. salary for job: Lead information systems engineer/ $116,291

MITRE, ranked 42d on Fortune's list, is a nonprofit researcher based in McLean, Va., that has its second largest location in Bedford. The Massachusetts site employs 1,884 people, and works on federally funded issues such as information technology and systems engineering for the Department of Defense, Federal Aviation Administration, and the Internal Revenue Service.