Google i:o

Google plays catch-up to Apple. Again.

It's that time of year again.

Google's I/O conference begins today and Apple's World Wide Developers Conference follows in a week and a half. Get ready for a barrage of competing leaks, releases and screaming headlines as each company tries to upstage the other, egged on by a click-hungry tech press.

Today it's Apple Pay. Tomorrow it will be something else.

We've come a long way since Steve Jobs called Android "a stolen product" and promised to destroy it. The rhetoric has cooled, but the issue is the same. Google copied Apple to make Android. It copied the App Store to make Google Play. It's copying Apple Pay to make Android Pay.

There's much to admire in Google. I'm awed by their willingness to tackle truly daunting engineering problems: Machine learning, Autonomous cars. Mapping the Internet. Mapping, for that matter, the world's roads and highways.

But Android was something different. It was a defensive play, and a sneaky one at that, given that Google had a seat on Apple's board of directors while the iPhone was in development.

Android was never as good as iOS, but it was good enough. It opened the door to Asia's fast followers, who flooded the market with me-too products.

Jobs may have seen what was coming when he threatened to go "thermonuclear" on Android. He turned to the courts for relief, but that too was a defensive play. Apple's strength comes from designing must-have devices we didn't know we needed, not from filing lawsuits, buying patents or adding features to keep up with the competition.

Last year, more than a billion Android devices were shipped, according to Gartner, five times as many as Apple. In terms of features and services, the two platforms have reached a rough parity.

If there's any consolation for the way Android vs. iOS turned out, it's that there seems to be room in the market for two dominant smartphone operating systems. And while the competition is still trying to figure out how to make money from Android, iOS has made Apple the most valuable company on the planet.

Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (aapl) coverage at fortune.com/ped or subscribe via his RSS feed.

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