Like many companies, Winnebago Industries Inc. wanted to reduce its reliance on mainframe technology and cut costs by implementing packaged software on cheaper hardware.

"We tried to move everything off the mainframe," says Dave Ennen, technical support manager at the $682 million-a-year maker of recreational vehicles. However, Winnebago's IT staff concluded they were messing with a system that worked well. "With most of the apps, we'd given the users what they wanted, and they couldn't see the reason for changing," Ennen says.

Winnebago moved its internally developed financial applications to an Infinium Software Inc. package running on a midrange IBM iSeries server. But the business kept its manufacturing, inventory, production scheduling, and E-mail apps on the mainframe.

	Winnebago's users were happy with the mainframe and didn't want to change, says technical support manager Ennen.

Winnebago has partitioned its S/390 Multiprise 3000 mainframe into 120 virtual servers--100 running IBM's VSE/ESA and CMS mainframe operating systems and the rest running Linux. By year's end, it plans to implement VSE/ESA 2.6, the latest version of the operating system. This is in preparation for an eventual upgrade to VSE/ESA 2.7, which will feature HiperSockets, a high-speed TCP/IP application that will integrate the VSE and Linux sides of the mainframe. HiperSockets will let Winnebago more quickly move files directly from the VSE to the Linux side of the mainframe. Without HiperSockets, Winnebago's IT department had to set up an external server to route data via File Transfer Protocol between the VSE/ESA and Linux sides of the mainframe.

Another reason for staying with the mainframe is that Windows NT "has been frustrating," Ennen says. "It's supposed to be a multipurpose server, but it only really runs one thing at a time." Plus, he says, when there are problems running more than one application on a single NT server, the application vendors tend to blame each other.

Winnebago's experience shows some of the reasons mainframes are still going strong. In addition, mainframes have shrunk in size and cost, yet still offer the most powerful and reliable computing environment available.

While Fujitsu and Hitachi have abandoned the North American mainframe market, IBM mainframes have been repurposed to handle the technology that's in demand--Linux and simplified systems management, to name two. What's more, IBM's other server lines continue to take on many mainframe characteristics, including autonomics, logical partitioning, and capacity on demand.

The mainframe's reliability and scalability have been widely chronicled for decades, but it's IBM's support for Linux on its zSeries mainframes that's bringing in new business. Last year, IBM won 75 new mainframe customers, breaking a years-long cycle of decline. By year's end, IBM expects to surpass last year's mark for new customers.

Most of the new customers are coming to the zSeries, formerly known as System/390, so they can run multiple iterations of Linux on the same machine. It's a more-efficient and less-expensive way to build a computing environment than to link up a bunch of Windows NT servers, says Richard Lechner, a VP for IBM's enterprise servers division. In fact, IBM says it has 500 customers using or testing Linux on the mainframe.

"Linux is a way to make mainframes more affordable and prove to customers that mainframe technology is moving forward," says Rich Partridge, an enterprise server analyst at D.H. Brown Associates.