Steve Jobs, co-founder and former chief executive of US technology giant Apple, has died at the age of 56.
Jobs has been suffering from pancreatic cancer since 2004.
The billionaire co-founder of Apple and the mastermind behind an empire of products that revolutionized computing, telephony and the music industry, had stepped down in August 2011 as chief executive of the company he helped set up in 1976, due to illness.
Jobs wrote in his letter of resignation: "I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's CEO, I would be the first to let you know. Unfortunately, that day has come."
US President Barack Obama said that with his death, the world had "lost a visionary".
“He made the information revolution not only accessible, but intuitive and fun”.
"Steve was among the greatest of American innovators - brave enough to think differently, bold enough to believe he could change the world, and talented enough to do it," said Mr Obama.
Apple said the company had "lost a visionary and creative genius, and the world has lost an amazing human being".
The bosses of other leading technology companies have also paid tribute, including Microsoft boss Bill Gates, who said Jobs's "profound impact" on the world of technology would "be felt for many generations to come".
"For those of us lucky enough to get to work with him, it's been an insanely great honour. I will miss Steve immensely."
Facebook founder Mark Zuckerberg thanks Mr Jobs for "showing that what you build can change the world".
Jobs introduced the colourful iMac computer, the iPod, the iPhone and the iPad to the world. His death came just a day after Apple unveiled its latest iPhone 4S model.
With a market value estimated at $351bn (£227bn), Apple is the world's most valuable technology company.
Copyright Speakers Corner 2017