US President Barack Obama has paid tribute to Apple co-founder and former CEO Steve Jobs.
"There may be no greater tribute to Steve's success than the fact that much of the world learned of his passing on a device he invented," the President said, shortly after Mr Jobs passed away aged 56.
Mr Jobs underwent an operation for pancreatic cancer in 2004 and a liver transplant in 2009, but had remained with Apple as chairman of the board of directors.
He resigned as CEO of the firm just two months before his death, handing over to Tim Cook as his health worsened.
"We are deeply saddened to announce that Steve Jobs passed away today", Apple said in a statement.
"Steve's brilliance, passion and energy were the source of countless innovations that enrich and improve all of our lives. The world is immeasurably better because of Steve".
"His greatest love was for his wife, Laurene, and his family. Our hearts go out to them and to all who were touched by his extraordinary gifts".
His family, in a separate statement, said Mr Jobs "died peacefully today surrounded by his family...We know many of you will mourn with us, and we ask that you respect our privacy during our time of grief," the Wall Street Journal reported.
Prime Minister Julia Gillard praised Mr Jobs as an "incredible global innovator", saying she was saddened to hear the news.
"It's not too much to say he literally changed our world," she added.
"All of us would be touched every day by products that he was the creative genius behind, so this is very sad news and my condolences go to his family and friends."
Mr Jobs resigned as Apple CEO in August with Tim Cook named as his successor.
Mr Cook mourned the loss of company co-founder, calling him a "creative genius" and "inspiring mentor."
"Apple has lost a visionary and creative genius, and the world has lost an amazing human being. Those of us who have been fortunate enough to know and work with Steve have lost a dear friend and an inspiring mentor," said Mr Cook, who took the company helm in August.
Mr Cook said the company was planning "a celebration of Steve's extraordinary life for Apple employees that will take place soon," and urged readers to share their memories of Jobs via e-mail at rememberingsteve@apple.com.
His death came a day after Apple unveiled the new iPhone 4S at its headquarters in California.
Hollywood and California hailed him as a titan of Silicon Valley, and a "rare original" who defined a cultural era.
Chris Dodd, head of the Motion Picture Association of America, Inc. (MPAA), highlighted Mr Jobs' visionary work at Pixar, the movie studio he founded while exiled for a time from Apple.
"The genius of Steve Jobs not only brought to life the visual magic and brilliant storytelling of Pixar, but brought the world one of the most innovative and successful platforms to make movies and TV available online.
Walt Disney Company boss Robert A. Iger paid tribute to Mr Jobs as a "rare original."
"His legacy will extend far beyond the products he created or the businesses he built. It will be the millions of people he inspired, the lives he changed, and the culture he defined," he said.
California Attorney General Kamala D. Harris meanwhile said the Golden State owed a huge debt of gratitude to Jobs.
"California has lost a great leader with the passing of Steve Jobs. His character, intelligence, and creativity changed how the world works and how the world imagines itself," she said.
Steve Jobs' death robbed the United States of a "genius" on a par with Einstein, New York Mayor Michael Bloomberg, who made billions of dollars with his own high-tech media company, said.
He said that New York's government, ranging from police to construction inspectors, "harnessed Apple's products to do their jobs more efficiently and intuitively."
