"When companies start to imitate one another, it's usually either an extreme case of flattery—or war. In the case of Google and Apple, it's both..."

Tensions in Silicon Valley's special relationship began to emerge in late 2007, when Google announced plans to develop Android for mobile phones. Apple had unveiled its iPhone in January of that year, and it was clear that the two companies would spar in the smartphone business. Still, both were niche players, with more formidable rivals in companies like Nokia (NOK), Samsung, and Research In Motion (RIMM). Only after software developers began creating thousands of mobile apps, and it became clear that phones would become the computers of the future, did the conflicts begin to grow serious. Last summer, Apple refused to approve two Google apps for sale to iPhone users, raising questions about how much of a Google presence Apple would allow on its devices. In August, Schmidt gave up his board seat. "Unfortunately, as Google enters more of Apple's core businesses," Jobs said at the time, "Eric's effectiveness as an Apple board member will be significantly diminished, since he will have to recuse himself from even larger portions of our meetings."