By AppleInsider Staff

Published: 03:00 PM EST

Apple's new iPhone, which isn't due to begin shipping until June, runs a version of the company's Mac OS X 10.5 "Leopard" operating system slated to ship around the same time, a published report said Thursday.

Writing for the Chicago Sun-Times, renowned Mac columnist Andy Ihnatko said he recently had the opportunity to spend 45 minutes with the iPhone, which features the "most beautiful freakin' display" he's ever seen on a cellphone of PDA "in range of color and level of detail."

"Everything I've learned (both in official briefings and 'you and I never spoke, all right?' sort of discussions) says that it truly does run Leopard, the upcoming 10.5 OS that will be released for the Macintosh late in the spring," he added.

Ihnatko went on to say that the spiffy user interface animations seen during Apple chief executive Steve Jobs' introduction of the device and subsequent demonstration all "come courtesy of Leopard's Core Animation suite."

Contrary to other first hand accounts, the columnist claims that the device's virtual keyboard "is a huge improvement over the mechanical thumbpads" found on the Treo and any other smart phones.

"The buttons are significantly larger, you don't have to hit them dead-center, you lightly tap them instead of punching them down, and the software is smart enough to know that you meant to type 'Tuesday' instead of 'Tudsday,'"he wrote.

"After 30 seconds," he continued "I was already typing faster with the iPhone than I ever have with any other phone."

Ihnatko's claims raise the possibility some of user interface attributes present on the iPhone could make their way into the version of Leopard that will ship for Apple's Mac line of personal computers.

Apple has maintained that Leopard is on track to ship later this spring.

For dozens of high-quality iPhone interface close-ups, check out our iPhone software photo gallery, iPhone hardware photo gallery and other galleries in our Macworld coverage news archive.