Apple released the latest version of its mobile operating system Monday bringing multitasking, folders, a unified inbox and wireless printing to the iPad.

Apple said iOS 4.2 for the iPad, the iPhone and iPad Touch offers more than 100 new features for the popular devices from the Cupertino, California-based company.

Apple chief executive Steve Jobs said the upgraded software, which can be downloaded for free from online entertainment store iTunes, "makes the iPad a completely new product."

"The iPad with iOS 4.2 will define the target that other tablets will aspire to, but very few, if any, will ever be able to hit," Jobs said in a statement.

Apple got the jump on its competitors with the launch of the iPad in April but a number of rivals have launched, or are planning to launch, their own touchscreen tablet computers including South Korea's Samsung and Canada's Research In Motion, maker of the Blackberry.

Many of the features in iOS 4.2 were already available for the latest versions of the iPhone and the iPod Touch but not for the iPad.

Apple said iPad users can now switch between applications instantly and run more than one at a time, playing a music program like Pandora, for example, while running another application.

Applications can now be organized into folders with a drag-and-drop feature.

Email features a unified inbox for users with more than one account while "Game Center" lets users of the iPad, iPhone and iPod Touch play against friends or other opponents and discover games that others are playing.

A new feature called "AirPlay" streams music, video and photos wirelessly from the iPad, iPhone and iPod Touch to a television set equipped with Apple TV, Apple's TV set-top box.

"AirPrint" allows an iPad owner to wirelessly print documents or photos to AirPrint-enabled printers from US computer maker Hewlett-Packard.

Apple said Monday that 40,000 applications have been created for the iPad and 300,000 for the iPhone and iPod Touch.