Microsoft is developing versions of Windows with only a subset of = its=20 code base, designed for specific server tasks. The intention is to re= duce=20 maintenance costs and create products that are less vulnerable to att= ack,=20 and so tackle head-on the threat posed by Linux. The new "role-based" products may appear in 2007, when the server= version of Longhorn is scheduled for release. Offering a smaller cod= e base=20 would mark a significant technical shift for Microsoft and could help= address the competitive threat posed by Linux. But it also presents= significant engineering challenges for the company, industry analyst= s=20 said. Microsoft already sells two role-based versions of Windows - one f= or=20 storage and one for Web serving. They essentially conceal from users = the=20 parts of Windows that are not needed for the task at hand, making the= m=20 easier to install and use. But those products still are based on the= entire Windows code base. With its Longhorn release, Microsoft hopes to offer role-based ver= sions=20 of Windows for tasks such as storage, file, or print serving that inc= lude=20 only a part of the overall Windows code, said Martin Taylor, Microsof= t=20 general manager for platform strategy. "Today, it's still the entire = code=20 base. There's no reduction in the bits you get - things are just rope= d=20 off," Taylor said. "We want to get to a model of role-based deploymen= t=20 where you might just have the bits you need for that function. It's o= ne of=20 our design goals for Longhorn." Many enterprises separate tasks such as e-mail and Web hosting,=20 assigning them to individual servers or groups of servers. Microsoft = would=20 continue to sell the full version of Windows for use as a general pur= pose=20 operating system, but could offer the role-based products for servers= assigned to particular tasks, he said. Such a move could benefit customers in two primary ways: better=20 security and lower maintenance costs, said Michael Cherry, lead analy= st at=20 Directions on Microsoft. Reducing the amount of code on a server woul= d=20 reduce the "attack surface area," Cherry said, meaning hackers would = have=20 less code to aim at with their viruses. A virus last month that targe= ted a=20 component for viewing jpeg image files affected Windows Server 2003, = he=20 noted, even though customers managing their servers remotely don't ne= ed=20 that component on their servers. Having less code should also mean lower maintenance costs, in part= because customers will not have to apply patches to the parts of Win= dows=20 that do not exist on their servers. "If you have a server whose role = is=20 definable and distinct, and you only load enough code to carry out th= at=20 role, then it's got to bring the total cost of ownership down," Cherr= y=20 said. A Microsoft spokeswoman confirmed that the goals of providing a sm= aller=20 Windows "footprint" are to cut maintenance costs and provide a "reduc= ed=20 surface attack area". Taylor didn't say whether the role-based server editions would be= cheaper than the full versions of Windows. The role-based products i= t=20 sells today - Windows Storage Server 2003 and Windows Server 2003 Web= Edition - are cheaper than the full versions of Windows Server 2003,= although usage restrictions apply. Removing parts of Windows presents engineering challenges. For=20 starters, Microsoft must ensure that ISVs can continue to write=20 applications without worrying about which components are available to= them, Taylor said. "The nice thing about Windows today is that Windo= ws is=20 Windows," he said. Microsoft is also keen not to limit the software's management=20 capabilities. For example, the current Web Edition of Windows cannot = serve=20 as a domain controller, which means it can't be used to manage group= policies, Internet authentication services and other tasks. "You hav= e=20 trade-offs in cost and trade-offs in manageability, so it's a fine=20 balance," Taylor said. He did not provide an exact timetable for the= products, but said development work is "pretty far down the path." <= /P> The proposed changes to Windows come as Microsoft faces perhaps it= s=20 toughest challenger yet in the form of Linux. The open source operati= ng=20 system has been growing among governments and businesses, in part bec= ause=20 some view it as a cheaper and more secure alternative. One advantage of the Linux source code being publically available = is=20 that customers can take the kernel apart and use only the components = they=20 want.