Prominent tech executives have pledged $1bn (£659m) for OpenAI, a non-profit venture that aims to develop artificial intelligence (AI) to benefit humanity.The venture`s backers include Tesla Motors and SpaceX CEO Elon Musk, Paypal co-founder Peter Thiel, Indian tech giant Infosys and Amazon Web Services.Open AI says it expects its research - free from financial obligations - to focus on a "positive human impact".Scientists have warned that advances in AI could ultimately threaten humanity.Mr Musk recently told students at the Massachusetts Institute of Technology (MIT) that AI was humanity`s "biggest existential threat".Last year, British theoretical physicist Stephen Hawking told the BBC AI could potentially "re-design itself at an ever increasing rate", superseding humans by outpacing biological evolution.However, other experts have argued that the risk of AI posing any threat to humans remains remote. -BBC