Andy Rubin, a vice president for engineering at Google, leads one of the search giant’s most important efforts—the development of Android, Google’s open source platform for smartphones and other mobile devices.

Android, of course, is Google’s primary weapon in its escalating battle with Apple over the smartphone market. Android currently runs on 9 percent of smartphones in the United States, according to Comscore.

It is also likely to be the company’s software choice for the emerging worlds of tablet computers and set-top boxes.

In a wide-ranging conversation on Google’s campus last week, Mr. Rubin talked about openness, support for Adobe Flash, Chrome, the upcoming Froyo release, and seemed to compare Apple to North Korea.

He predictably said that the Android platform was taking off because it was open to many manufacturers running many different architectures.

“It’s a numbers game. When you have multiple O.E.M.’s building multiple products in multiple product categories, it’s just a matter of time” before sales of Android phones exceed the sales of proprietary systems like Apple’s and R.I.M.’s, he said.

As to when the number of Android phones sold would exceed the number of BlackBerrys and iPhones sold, Mr. Rubin said, “I don’t know when its might be, but I’m confident it will happen. Open usually wins.”

I also asked him about the Apple chief executive Steve Jobs’s recent comment that “folks who want porn can buy an Android phone.”

“I don’t really have a rationale for that,” he said. “It’s a different style of interacting with the public and the media.”

Mr. Rubin also addressed many other topics — like whether consumers actually care if their mobile phone software is “open” or not. He insisted that they would, comparing closed computing platforms to totalitarian governments that deprived their citizens of choice. “When they can’t have something, people do care. Look at the way politics work. I just don’t want to live in North Korea,” he said.

When asked whether Android apps from Google might have an advantage over other companies’ apps in the Android Market, the discussion again seemed to implicitly veer toward Brand X.

“We use the same tools we expect our third-party developers to,” Mr. Rubin said. “We have an SDK we give to developers. and when we write our Gmail app, we use the same SDK. A lot of guys have private APIs. We don’t. That’s on policy and on technology. If there’s a secret API to hook into billing system we open up that billing system to third parties. If there’s a secret API to allow application multitasking, we open it up. There are no secret APIs. That is important to highlight for Android sake. Open is open and we live by our own implementations.”

He also promised that full support for Adobe’s Flash standard was coming in the next version of Android, code-named Froyo, for frozen yogurt (previous Android releases were called Cupcake, Donut and Eclair, and are represented outside Building 44 on the Google campus with giant sculptures of the desserts). Sometimes being open “means not being militant about the things consumer are actually enjoying,” he said.

Of the fear that Android could “fork” into various different versions, making it difficult for application developers to create one program for all Android devices, Mr. Rubin compared the platform with every other PC operating system.

These systems naturally evolve, causing newer applications to not be compatible with older devices. “But compatibility for us means more than it does for other people,” Mr. Rubin said. “We have to run on a screen the size of a phone and a 42-inch plasma display — and still be compatible. I think we have the world’s first moment where an app written for phone can run on TV.”

I also asked about how Google was viewing its Android and Chrome operating systems – and which was the company’s preferred software for devices like tablet computers. He said the two platforms represented two different ambitions at Google – improving access to information on mobile phones, in the case of Android, and pushing forward the open Web in the case of the Chrome operating system.

The efforts are not necessarily mutually exclusive, Mr. Rubin said. “I don’t know if there will be Chrome and Android tablets, but if a consumer walks into store and two of those tablets are my company’s choices, I’m all good.”

Mr. Rubin said he owned an iPad; he purchased one for his wife. He said that such tablets should have traction among “a certain demographic that consumes more than produces,” but that they will likely eat into laptop sales, instead of creating an additional market. “I don’t think people want to charge another device,” he said.

At the end of the hourlong chat, I joked with Mr. Rubin that his press relations colleague, who was in the room, wanted to confess that he had left a prototype Android phone at a local bar.

“I’d be happy if that happened and someone wrote about it,” Mr. Rubin said. “With openness comes less secrets.”