Computer sharing loses momentum

T he family of '@home' volunteer computing projects is growing ever more diverse. Spare time on a personal computer can now be donated to anything from finding alien life to crunching climate models or processing photos of asteroids. But enthusiasm is waning. The 47 projects hosted on BOINC, the most popular software system for @home efforts, have 245,000 active users among their 2.7 million registrants, down from a peak of about 350,000 active users in 2008 (see 'Slumping @home'). has several explanations for the slip. He says media coverage has declined now that volunteer computing is more than 15 years old. A shift to mobile-computing devices has probably also hurt — BOINC can run on an Android phone while charging, but uses too much battery power when unplugged. And the site has been unable to attract a broad demographic of volunteers. " Essentially, we have a bunch of middle-aged, male computer nerds, " says Anderson. " We have thought long and hard about ways to break out of that category, using Facebook, for example, but none of that has been all that successful. " On 20–22 February, at the 3rd Citizen Cyberscience Summit in London, conference-goers will trade tips on how to entice volunteers into projects ranging from BOINC-style distributed computing to more-active 'citizen-science' projects, in which users are asked to donate not just their time but also their brains. The desire to keep numbers up is not just academic. If distributed computing flourishes, serious money can be saved, says Francois Grey, coordinator of the Citizen Cyberscience Centre, based in Geneva, Switzerland. He notes that the Chinese Academy of Sciences in Beijing has been monitoring the economic benefits of CAS@home, which uses volunteers' computing time for projects such as predicting protein structures. The academy estimates that US$20 million has been saved since it launched CAS@home in September 2010, by using donated computing power rather than buying it from a company such as Amazon. Grey predicts that funding bodies might at some point enforce the use of volunteer computing whenever possible, rather than allowing grant money to be used for supercomputer time or cloud-based services. " It's very delicate. There are big IT companies with vested interests in selling supercomputers to universities, " he says. " But I think it's something that will happen at some point. " For volunteer computing to be used in a bigger way, participation rates need …