Tributes from around the world have poured into Apple co-founder Steve Jobs who has died at the age of 56.

The US technology company announced that its pioneering former chief executive, who gave the world the revolutionary iPhone and iPad devices, died yesterday surrounded by his family after battling pancreatic cancer.

He stepped down from his post as Apple's chief executive in August, no longer able to handle the job due to his illness.

Today, tributes flooded in for the man who changed the way the world thinks about technology.

Bill Gates, founder of rival company Microsoft and a friend of Mr Jobs, said he would miss him 'immensely'.

'The world rarely sees someone who has had the profound impact Steve has had, the effects of which will be felt for many generations to come,' he added.

US President Barack Obama also paid tribute to Mr Jobs, saying 'the world has lost a visionary'.

In a statement he said: '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.

'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.

'The world has lost a visionary. And 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.'

Lord Sugar remembered his Amstrad computer company competing with Mr Jobs in the 1980s.

He wrote on Twitter: 'Gutted: Steve Jobs died.

'We started our computer biz at same time and were competitors thru 80's. Great visionary. Sadly missed RIP.'

Facebook founder Mark Zuckerberg wrote on his Facebook page: 'Steve, thank you for being a mentor and a friend. Thanks for showing that what you build can change the world. I will miss you.'

Apple said it was 'deeply saddened' by the news.

A statement released by Mr Jobs' family said: 'Steve died peacefully surrounded by his family.

'In his public life, Steve was known as a visionary; in his private life, he cherished his family.

'We are thankful to the many people who have shared their wishes and prayers during the last year of Steve's illness.

'We know many of you will mourn with us, and we ask that you respect our privacy during our time of grief.'

The father-of-four started Apple Computer with school friend Steve Wozniak in his garage in 1976 but was forced out a decade later.

He returned in the mid-1990s and transformed Apple into one of the world's most powerful companies.

Just two months ago the frail-looking businessman resigned as the company's chief executive due to his ill-health, but said he would continue to play a leadership role.

He was replaced by Apple's chief operating officer, Tim Cook, and took the role of chairman of the company's board.

In a letter addressed to Apple's board, the entrepreneur said he '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'.

Mr Jobs, described by many as an industry oracle who revolutionised computing, survived pancreatic cancer in 2004 before receiving a liver transplant in 2009.

He had taken three spells of leave over the past several years, most recently in January.

After quitting Apple in 1985, Mr Jobs went on to co-found Pixar Animation Studios, which has created some of the most successful animated films of all time including Toy Story, A Bug's Life and Finding Nemo.

In 2006, he sold Pixar to The Walt Disney Company and secured a seat on the board.

He returned to Apple as an adviser in 1996 - the year it lost $900m (�580m) as Microsoft Windows-based PCs dominated the computer market.

However, the tide started to turn following the hugely successful 1998 release of the iMac and Mr Jobs later became chief executive.

Apple's popularity grew across the world throughout the past decade with the introduction of its sleek line of iPods, the iPhone and more recently the iPad.

Mr Cook said Apple had 'lost a visionary and creative genius'.

In an email circulated to staff, he said: 'Steve leaves behind a company that only he could have built, and his spirit will forever be the foundation of Apple.

'No words can adequately express our sadness at Steve's death or our gratitude for the opportunity to work with him.

'We will honour his memory by dedicating ourselves to continuing the work he loved so much.'