Former Apple (AAPL) CEO Steve Jobs was remembered on Wednesday as a technology icon whose drive and creativity forever changed Silicon Valley and the way millions of people around the globe communicate with each other.

Jobs “exemplified the spirit of American ingenuity,” President Barack Obama said in a statement.

“Steve was fond of saying that he lived every day like it was his last,” Obama said. “Because he did, he transformed our lives, redefined entire industries, and achieved one of the rarest feats in human history: he changed the way each of us sees the world.”

Apple announced Jobs’ death shortly after 4:30 p.m., saying in a statement: “We are deeply saddened to announce that Steve Jobs passed away today.

“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.”

Apple didn’t release details of Jobs’ death, such as when he died or the cause and a company spokeswoman declined to comment beyond the statement the company released. Jobs was 56.

In honor of its legendary founder, Apple remade its Web site, putting a picture of Jobs front and center on its home page. By clicking on the picture, users were greeted with a statement about him from the company.

“Apple has lost a visionary and creative genius and the world has lost an amazing human being,” the Apple page said. “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.”

Numerous tech lumniaries echoed the company’s praise.

“From the earliest days of Google (GOOG), whenever Larry and I sought inspiration for vision and leadership, we needed to look no farther than Cupertino,” Google co-founder Sergey Brin said in a statement. “Steve, your passion for excellence is felt by anyone who has ever touched an Apple product (including the macbook I am writing this on right now).”

He added: “On behalf of all of us at Google and more broadly in technology, you will be missed very much.”

Google CEO Larry Page and Facebook CEO Mark Zuckerberg both thanked Jobs for mentoring them. Page said Jobs contacted him after he took over Google earlier this year.

“He was very kind to reach out to me … and spend time offering his advice and knowledge even though he was not at all well,” Page said in a post on Google+. “He always seemed to be able to say in very few words what you actually should have been thinking before you thought it. His focus on the user experience above all else has always been an inspiration to me.”

“Thanks for showing that what you build can change the world,” Zuckerberg said in a post on Facebook. “I will miss you.”

Others outside of the tech industry also publicly mourned Jobs’ passing. In a statement released by Disney, company CEO Bob Iger called Jobs, who served on Disney’s board, a “great friend and trusted advisor.”

“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,” Iger said in the statement. “Despite all he accomplished, it feels like he was just getting started.”

California Governor Jerry Brown called Jobs a “great California innovator.”

Jobs “demonstrated what a totally independent and creative mind can accomplish,” Brown said in a statement. “Few people have made such a powerful and elegant imprint on our lives.”

Praise of Jobs and sadness at his passing was widespread in postings on social networks such as Twitter and Facebook.

“I don’t think I’ve ever been so affected by the death of someone I never met,” wrote one Twitter user. “He was an icon and an inspiration.”

The widespread praise of Jobs following his death stood in contrast to the criticism and controvery he and his company often generated during his life. He was ousted from Apple in the mid-80s after a contenttious leadership battle. He was known to be harshly critical of employees, partners, rivals and the media. And he was involved in a options backdating scheme that forced the departure of two Apple executives.

Word of Jobs’ death came less than two months after Jobs stepped down as Apple’s CEO. Citing his inability to continue to “meet the duties and expectations” of heading the Cupertino company, Jobs resigned that role on Aug. 24. Apple named Tim Cook, then the company’s chief operating officer, as its new CEO and named Jobs its chairman.

Jobs’ resignation followed a medical leave that began in mid-January. When he announced the leave, his third since 2004, he left its duration open-ended, raising speculation about his long-term health.

Jobs took a six-month leave in 2009, during which he underwent a liver transplant. He also took a brief leave in 2004, during which he underwent a successful surgery for a rare, treatable form of pancreatic cancer.

Despite his ongoing health problems, Jobs did make occasional public appearances. He was on hand last year to unveil the original iPad, and this past summer he showed up at a Cupertino City Council meeting to present his plans for a new Apple campus.

Cook, who handled day-to-day operations of the company while Jobs was on leave in 2009, had impressed analysts. And during that time Apple released the wildly successful iPhone 3GS, while the iPad was under development.

Jobs led the company from its founding in 1976 until he was forced out in a leadership struggle in 1985. He returned to the company in 1996, when Apple bought Next, the computing company that Jobs founded after he left Apple. With Apple teetering on bankruptcy, Jobs assumed control of the company the following year, first as its interim CEO, then as its full-time one.

During his first tenure at Apple, Jobs helped develop the original Apple I and Apple II computers, then worked on the Macintosh, the first mass-market computer with a graphical user interface. Although the Mac never dominated the industry, its basic mouse-and-virtual desktop interface became the standard way of interacting with PCs.

Once he returned to Apple, Jobs helped lead the company’s amazing resurrection. The company went from being within months of bankruptcy in 1997 to vying this year for the title of most valuable company in the world.

The company’s rebound was driven initially by the iPod music player and the iTunes software and store, which together offered consumers a legitimate and easy way to buy and listen to digital music. More recently, the company has had huge hits with its iPhone smartphone and iPad tablet computer.

Even as Apple’s stock soared along with its parade of product hits, worries over Jobs’ lingering health problems continued. And with each new medical leave, concerns mounted that Jobs’ days as head of the company he co-founded in 1976 would soon be over. A recent report in Fortune magazine said that Jobs started thinking seriously about stepping down as CEO in late July, according to people close to him, because returning full time to Apple was increasingly doubtful.

“These people say that Jobs suffers ups and downs,” the report said. “Some days he is able to hold meetings and weigh in on decisions. Some days he remains housebound and cancels appointments. While he could have chosen the status quo — remaining CEO, with Cook leading day-to-day operations — Jobs decided to take the next step in the transition.”

In public sightings and tabloid photos, Jobs looked increasingly frail and gaunt, a condition complicated by the company’s own obsession with secrecy around its leader. It was a troubling image, especially compared with the sort of youthful exuberance that Jobs had shown for so many years. With the CEO’s boyish all-in-one personality of product guru, gung-ho showman and salesman extraordinaire, it was often hard to tell where the line between the man and his shimmering creations really lay.

Yet through it all, analysts as well as longtime colleagues insisted that Jobs had assembled a brilliant management team and that Apple, at least for the next three to five years, would remain on solid footing.

“The Apple culture is bigger than any one individual,” Jobs’ longtime friend and valley marketing pioneer Regis McKenna said recently. “There’s a DNA in Apple that Steve helped nurture and it will carry on in the enthusiasm of the people he’s put in place there.

“It was an enthusiasm that Steve always had,” McKenna said. “He’d get really lost in a new product and he’d pause and say, ‘Oh, that’s so cool.’ Even in the dark days, he once said to me ‘I love what I’m doing and I want to keep doing it.'”

Jobs is survived by his wife, Laurene Powell Jobs; his sister, novelist Mona Simpson; and four children: son Reed, and daughters Lisa Brennan-Jobs, and Erin and Eve Jobs .

Contact Troy Wolverton at 408-840-4285. Follow him on Twitter at http://twitter.com/troywolv.