A former partner in leading Silicon Valley venture capital firm Sequoia Capital has countersued a woman who claimed he sexually abused her for more than a decade, arguing she was trying to extort $40 million from him.

An IBM supercomputer developed for US government nuclear simulations, and to study climate change and the human genome has been recognised as the world’s fastest.

Two Limerick brothers who became millionaires while still at school have seen their newest venture, Stripe, valued at €75 million.