Steve Jobs, Apple's visionary co-founder and chairman, has died. He was 56.

Jobs had stepped down as CEO in August due to health problems. He had been previously stricken with pancreatic cancer and had struggled with health issues since 2004.

"Steve died peacefully today surrounded by his family," his relatives said in a brief statement.

"In his public life, Steve was known as a visionary; in his private life, he cherished his family. We are grateful for the support and kindness of those who share our feelings for Steve."

Apple announced his death without naming a specific cause.

The company's new CEO, Tim Cook, broke the news to staff in an email Wednesday.

"I have some very sad news to share with all of you. Steve passed away earlier today," he wrote.

"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. Steve leaves behind a company that only he could have built, and his spirit will forever be the foundation of Apple.

"We are planning a celebration of Steve's extraordinary life for Apple employees that will take place soon."

Apple, the United States' most valuable company and arguably the world's most-loved technology brand, asked those who wanted to share their thoughts and condolences to email

U.S. President Barack Obama tweeted what was on the mind of many people Wednesday night.

"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," Obama wrote.

In a formal statement, Obama said that Jobs was bold enough to believe he could change the world, and with his talent, he did.

Jobs had been suffering from health problems since being diagnosed with a rare form of pancreatic cancer in August 2004. In 2009, Jobs underwent a liver transplant during a six-month medical leave of absence.

He was back at the helm of Apple, sporting his iconic black turtlenecks and toting his company's revolutionary products, for a year and a half before he was forced to step down for a final time.

"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," Jobs told his employees at the time.

After dropping out of college, Jobs, along with Steve Wozniak and Ronald Wayne, founded Apple in 1976, virtually inventing the concept of personal computing.

He would then go one to radically transform several other industries in the coming decades, forever changing the way we listen to music with the invention of the iPod, and the way we communicate with the introduction of the iPhone.

And with the release of the iPad in 2010, the brilliant touch-screen tablet computer that we never knew we wanted, Jobs secured his position as one of the most visionary and successful entrepreneurs in American history.

Even in his time outside of Apple after being asked to resign in 1985, Jobs managed to have a Midas touch. He co-founded the visual effects company, Pixar, which became the animation studio behind classic films such as "Toy Story," "Finding Nemo" and "WALL-E."

He returned to Apple in 1997 as its CEO, and sold his Pixar majority share in 2006 to The Walt Disney Company, where he was named to that company's board of directors.

Apple lost $2 billion in the two years prior to bringing Jobs back. He quickly went about streamlining the company and focusing on the design and consumer markets.

A year later, the iconic iMac was launched and Apple had a hit product on its hands. In 2001, the iPod was released, flipping the music industry on its head.

In 2006, author Steven Levy wrote "The Perfect Thing: How the iPod Shuffles Commerce, Culture, and Coolness."

"The iPod was really the pivotal device for this century which showed that technology could not transform our lives but also be an object of lust, in and among itself," he told Wednesday, only hours before it was learned that Jobs died.

The news of Jobs' death comes one day after Apple unveiled its latest version of the iPhone. Before the news of Jobs' death, a group of Apple fans had declared Oct. 14, the day the new iPhone 4S is to be released, to be "Steve Jobs Day."

For many of Apple's fans, of which there are millions in the die-hard variety, Jobs was more than a businessman -- he was the Apple brand. Considering he was a billionaire many, many times over, to be that loved is a remarkable achievement.

Jobs leaves behind his wife, Laurene Powell Jobs, and four children.

In 2005, Jobs gave the commencement address at Stanford University, a speech called "How to live before you die."

"Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life," he told graduates. "Because almost everything -- all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart."

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