Steve Jobs returned to his showman's role at Apple as he led the launch of an updated range of iPods and a new package of digital goodies for music fans.
The Apple chief executive, looking thin but full of energy after a liver transplant, has not been seen in public since he went on medical leave at the start of the year.
His appearance triggered a standing ovation from Apple employees in the auditorium at the media event in San Francisco.
"I'm vertical, back at Apple and loving every day of it," Jobs said as the company's shares surged 1 per cent.
He led executives in an annual unveiling of new features for Apple's successful digital music players and announced an update for the iTunes popular online media store.
The biggest hardware innovation was a video camera and built-in FM radio for the iPod Nano. Apple also stepped back in time to launch the “iTunes LP” feature for music lovers who remember the old days of liner notes, lyrics and other extras when they bought albums.
In the digital age, consumers have deserted albums to buy single tracks and Apple has partnered with music publishers to offer the new packages and boost sales.
Jobs, 54, whose vision and drive have led Apple to become the top consumer electronics brand in the world, said he was happy to be back. He wore his trademark long-sleeved black shirt, jeans and sneakers but as thin as during his last appearance on stage in October 2008.
“About five months ago I had a liver transplant," he said. "So I now have the liver of a mid-20s person who died in a car crash and was generous enough to donate their organs." He said he would not be alive without the donor's generosity and urged others to sign up to become organ donors.