This was Jobs first public appearance after Oct 2008. The 54-year-old who returned to work in June had a liver transplant about five-months ago.
Sporting a long-sleeved black t shirt and jeans, Mr Jobs said, "About five months ago I had a liver transplant. 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. I hope all of us can be as generous and elect to be organ donors."
Jobs addressed the huge gathering of Apple employees, journalists, bloggers, and software developers in highly personal terms striding up and down the stage.
As soon as Jobs mentioned Twitter in his keynote address, the microblogging site went down for about 15 minutes. The users were met with a 'HTTP Server Error 503', The Telegraph reports.