Google today launched a version of its Chrome browser for iOS, the Apple mobile operating system that powers the iPhone and iPad.
The company confirmed that the browser is essentially Safari in disguise, as Chrome relies on Apple's browser and JavaScript engines, with additional features and a Google user interface (UI) wrapped around the outside.
The surprise announcement was made by Brian Rakowski, a vice president of product management responsible for Google's browser, during a keynote on the second day of the company's annual I/O developers conference.
"Later today, we'll be rolling out [Chrome] in the App Store," said Rakowski during his part of the presentation, which was largely a recap of Chrome's growth and a highlight or two of already-present features.
Chrome for iOS can be downloaded free-of-charge from Apple's App Store.
Although some had speculated that Chrome would arrive on the App Store -- in mid-May analysts with Macquarie Equities Research pegged the possibility as soon as the second quarter, which ends June 30 -- there had been almost no hints of today's announcement in the technology press.
Chrome will run on iOS 4.3 or later -- the current version is 5.1.1, with iOS 6 expected to launch this fall -- on both the iPhone and iPad, with separate versions for each device's screen format, Rakowski said.
Apple's own Safari -- a version specific to iOS, although similar in functionality to the OS X desktop edition -- is the default browser for the iPhone and iPad. Alternatives have been scare, and mostly restricted to small efforts from small developers.
That's because Apple's App Store guidelines, which spell out what's permitted and what's not by iOS app makers, are very specific about the rules for browsers.
"Apps that browse the Web must use the iOS WebKit framework and WebKit JavaScript," state the current version of the guidelines.
One of the top-five browser makers, Norway's Opera Software, has circumvented the rule, and had its Opera Mini approved for App Store distribution, because its software isn't really a stand-alone browser. Instead, Opera Mini is a proxy that takes URL requests, sends them to Opera's servers, where the pages are rendered and compressed before the data heads back to the device.
Opera Mini debuted on the App Store in April 2010.
Apple has not suddenly voided the WebKit requirements, as Google confirmed today. "Rendering and the JavaScript engine are provided by iOS through UIWebView, so Chrome for iOS does not use Chrome V8 JavaScript engine," a Google spokeswoman said in an email reply to questions.
"Chrome for iOS provides the same fast, secure and stable Web browsing experience you've come to enjoy when using Chrome on your desktop or Android device, while also adapting to platform specific technical specifications," she added.
Google, like Apple, relies on the open-source WebKit browser engine to power Chrome, but the iOS version's reliance on Safari's rendering engine, as well as on Apple's JavaScript engine, should make Chrome on par with, but not faster than, Safari.
Rakowski quickly demonstrated Chrome's already-in-place synchronization feature working in the iOS edition, indicating that users can sync bookmarks, passwords, open tabs and other information there with browsers on different devices, including Macs and Windows PCs.
Earlier this week, Google quietly shipped Chrome 20 for the desktop with patches for 22 security vulnerabilities. However, Chrome for iOS is based on the previous version, Chrome 19, said Google. Chrome 19 launched in mid-May.
On Wednesday, Google released the first edition of Chrome for Android in its "stable" channel, the version suitable for production use and the most reliable version Google maintains.
Also today, Google released Google Drive for iOS. Google Drive requires iOS 5.0 or later.
