The Problem Most companies have scores of servers and desktop systems that sit idle much of the time. What a waste! Why not put those unoccupied processors to use on some of your biggest computing problems?The Hype IBM, Sun and other major vendors are all abuzz about grid computing. The basic idea of grid (a.k.a. "distributed computing" in its previous, more academic incarnation) is this: Tie many small computers together and use them as a sort of supercomputer. Biotech and animation companies?both of which require massive computing firepower for gene sequencing and scene rendering, respectively?report early successes with grid technology. In the long-term grid vision, users will be able to harness grid-computing power even outside their firewalls. Businesses will plug into the grid and tap that power?and pay for it?only as needed, just like electricity. Throw the light switch on, the juice starts flowing and the meter starts running. Turn the switch off, the meter stops. No more wasted capacity.The Facts Critics of grid computing point out that interenterprise grids face considerable security hurdles (see "Power Pool," Emerging Technology, April 1, 2002). However, most companies will aim to build internal grids first, using only the resources behind their firewalls. Even there, most enterprises will have to wait for the maturation of another emerging technology?Web services?before grids can hit the mainstream.The reason is simple: Most applications were not written to run in a distributed manner. "Applications are the number-one barrier," says Songnian Zhou, CTO, chairman and cofounder of Markham, Ontario-based grid vendor Platform Computing. "Every time you shift architecture?mainframe to PCs [for example]?the apps you are going to use were designed before this era." In fact, the inability to break monolithic business applications into bite-size pieces is one of the hurdles that has kept the oft-promised mainstream arrival of massively parallel computing hardware?which effectively does in one machine what a grid does across many?out of the mainstream for decades.Meta Group Service Director Nick Gall says there is progress. Web services offers a promising attempt at making applications more granular (see "Make Way for Web Services," at www.cio.com\/archive). David Knight, vice president of applications and business services at Portera, a Web services hosting company in Campbell, Calif., says that\u2019s simply because developers are writing new applications from the ground up with the distributed processor model in mind. Still, it will take some time?perhaps a couple of years?for the vendors to recast today\u2019s commercial off-the-shelf software into a grid-friendly mold.