In 2004, Berners-Lee was knighted by Queen Elizabeth II for his pioneering work.[14][15] In April 2009, he was elected a foreign associate of the United States National Academy of Sciences.[16][17] He was honoured as the "Inventor of the World Wide Web" during the 2012 Summer Olympics opening ceremony, in which he appeared in person, working with a vintage NeXT Computer at the London Olympic Stadium.[18] He tweeted "This is for everyone",[19] which instantly was spelled out in LCD lights attached to the chairs of the 80,000 people in the audience.[18]