Some 25 percent of those surveyed chose Red Hat Linux as a viable alternative to Vista, while SUSE Linux and Ubuntu each attracted 18 percent of respondents. "Clearly many companies are serious about this alternative, with 9 percent of those saying they have considered non-Windows operating systems already in the process of switching and a further 25 percent expecting to switch within the next year." Most concerns about upgrading to Vista revolve around stability, according to NetworkWorld, although compatibility with business software required to run on Vista was also often cited. Some IT pros pointed to cost as a source for concern about upgrading to Vista. Many of the professionals polled said virtualization -- a technology allowing one computer with compatible hardware to run foreign software at near-native speeds -- is a key to veering away from Microsoft's technology. Other challenges still face IT departments looking to steer clear of Vista, however. The survey found that 49 percent of respondents need to manage multiple operating systems, while 50 percent said they would need to learn a different set of management tools. No less than 60 percent of IT professionals polled said they manage their Windows installations with tools that don't support non-Windows systems. Some 45 percent of survey participants mentioned challenges with system management in non-Windows operating systems as a barrier to adopting alternatives to Vista.