That very short list explains in part why, for all its success in the phone business, Apple suddenly has a real fight on its hands.
Americans now are buying more Android phones than iPhones. If that trend continues, analysts say that in little more than a year, Android will have erased the iPhone’s once enormous lead in the high end of the smartphone market.
But this is not the first time Apple has found itself in this kind of fight, where its flagship product is under siege from a loose alliance of rivals selling dozens of competing gadgets.
In the early 1980s, the Macintosh faced an onslaught of competition from an army of PC makers whose products ran Microsoft software. The fight did not end well for Apple. In a few years, Microsoft all but sidelined Apple, and the company almost went out of business.
Can Apple, which insists on tight control of its devices, win in an intensely competitive market against rivals that are openly licensing their software to scores of companies? It faces that challenge not only in phones, but also in the market for tablet computers, where the iPad is about to take on a similar set of rivals.
“This is a really big strategic question,” said Toni Sacconaghi, an analyst with Sanford C. Bernstein and Company. “No one knows whether openness will ultimately prevail as it did on the PC.”
Apple declined to comment on the issue.
By some measures, the competition Apple faces this time is even more formidable than it was in PCs. In addition to the Android family, Apple already competes with Research In Motion, maker of the BlackBerry.
And the iPhone will soon have one more powerful, and familiar, foe: Microsoft. That company’s well-reviewed Windows Phone 7 software will appear in as many as nine new smartphones beginning next month. Others like Nokia cannot be counted out.
The stakes are huge, as the mobile computing market could prove to be larger than the PC market ever was.
No one is counting out Apple, of course. The iPhone 4, which Apple began selling this year, has been its most successful phone introduction yet. On Monday, when the company reports financial results, it is expected to announce that it sold nearly 12 million iPhones in the quarter ending Sept. 25, according to analysts’ estimates. That would represent a 60 percent increase from a year earlier.
And with Apple expected to bring the iPhone to Verizon early next year — most likely in an attempt to slow Android’s momentum — the sales growth may well accelerate.
Among investors, there is little doubt that Apple’s strategy is the right one. The company’s stock has soared nearly 50 percent this year, and on Friday it closed at an all-time high of $314.74.
But the rise of Android has been both sudden and unexpected, and its ascent highlights some of the advantages of an open approach.
“There is much more rapid innovation taking place in an open environment,” said David B. Yoffie, a professor at the Harvard Business School who has written recent case studies on Apple. While Apple comes out with a new iPhone model once a year, slick Android phones with new features hit the market often.