Economics Report.Changes are taking placein Silicon Valley in California.Larry Page will replace Eric Schmidtas chief executive at Google.And Apple's chief, Steve Jobs,is taking another medical leave.Two years ago Mr. Jobsreceived a new liver.In two thousand fourhe had pancreatic cancer.This month's announcementdid not say how long he mightbe away or give a reason.Apple reported record-high earningsfor the final three months of last year.But the health of Steve Jobsalways brings questionsabout the future of the company.He helped start Apple Computerin nineteen seventy-six.Today the companythat played a big partin the personal computing revolutionjust calls itself Apple.Its products include the iPodand iPhone, and it expectsto sell six millioniPad tablet computers this year.Steve Jobs has long beenApple's public face.But some might forget that he leftin nineteen eighty-five to forma computer company called NeXT.Manuel Perez-Quinonesis a computer science professorat Virginia Tech.He says Apple has led the developmentof some technologies,but that explainsonly part of its success.MANUEL PEREZ-QUINONES: "Apple has beena driver in some thingsand they have been a faithfuladopter of good ideas in others."For example, he saysmany development toolsassociated today with Applecame from NeXT.MANUEL PEREZ-QUINONES: "The developmentenvironment, the programming languages,some of the libraries that are usedwere things that Steve Jobswas very tightly connectedto from the very beginning.But it was not necessarily at Apple.It came from NeXT Computer."Apple bought NeXT in nineteen ninety-six.Mr. Jobs rejoined Apple and becamethe permanent CEO in two thousand.Last May, Apple passed Microsoftin market value and becamethe most valuable technology companyin the world.Mr. Jobs says he will remainchief executive officerand stay involved in major decisionsduring his medical leave.But he put Tim Cook,his chief operating officer,in control of daily operations.As Steve Jobs steps back at Apple,Eric Schmidt is stepping down at Google.Mr. Schmidt plans to leave his CEO jobin April after almost ten years.He will remain on Google's board of directors.Larry Page was Google's founding CEOwhen he launched the companywith Sergey Brin in nineteen ninety-eight.But Mr. Schmidt has been the public faceof Google while Mr. Pagehas mainly worked on new products.Today Google is the world leaderin Internet search and has productslike the Android operating systemfor mobile devices.But Google is seen as tryingto recapture the creative energyand speed of its early days.And that's the VOA Special EnglishEconomics Report,written by Mario Ritter.