Headquarters: Cupertino, Calif.
Revenue: $156.5 billion
Profit: $41.7 billion
2012 rank: 17
Making its Fortune Top 10 debut, the software giant is the biggest mover in the bunch, leaping 11 spots from No. 17 to No. 6 in a single year. Revenues for Apple grew by 44 percent in 2012, and profits grew by 61 percent. Its biggest competitor in the computer industry, Hewlett Packard, suffered the biggest single-year revenue loss of any company on the Fortune 500, dropping out of the Top 10.