Apple has announced what is arguably the biggest update to the iPhone operating system yet, adding features that have been requested since the device's debut.
Foremost among the additions in iPhone OS 4.0, which will be available this summer, is multitasking for third-party apps. Previously, only specific apps made by Apple were allowed to run simultaneously, including the iPod and mail. In OS 4.0, developers can enable specific tasks to run in the background, and users can switch between apps by double-tapping the Home button, which brings up a dock that shows all open applications.
So it's not full multitasking, like you get on a computer. Apps are restricted to a handful of background features, including audio, location, voice over IP, task completion (such as uploading a photo) and notifications. Apple said this is the only way to offer multitasking while conserving battery life and keeping foreground apps running fast. One big downer for iPhone 2G and 3G owners: multitasking won't be supported.
Another feature that will delight app fiends is folders. Users will be able to create folders full of apps, instead of having them all shown on the Home screen. And at last, users will be able to add a background wallpaper to the Home screen, just like the iPad.
The iPhone's Mail app is also getting a boost. Unified inbox will allow users to read several mailboxes in one stream, and they can now view messages in thread form (like Gmail) and open attachments into specific apps, allowing you to, say, upload an e-mailed photo directly to Flickr.
For gamers, Apple is launching GameCenter, sort of like an Xbox Live service that provides achievements, leaderboards and matchmaking. It's kind of like the OpenFeint and Plus+ networks that exist now, but with better features for inviting people to play and finding other people to play against.
Other features of iPhone OS 4.0 include the iBooks app, playlist creation, 5x digital zoom for the camera, touch-to-focus for video and support for Bluetooth keyboards. Apple also demonstrated a new kind of advertising that app developers can use.
It's a little disappointing that Apple didn't announce any revolutionary features for OS 4.0. Many of the ideas -- folders, multitasking, even GameCenter -- have been done before, but they'll go a long way towards satisfying iPhone users who've grumbled about these missing features for years.
