Jim Shallis, director of consulting services, CGI:

If you're running mission-critical, high-volume transaction processing, where the margins for error and downtime are virtually nil, UNIX beats NT every time. With UNIX, expandability is inherent. It has better load-balancing capabilities, is fully C2 compliant, and supports a multi-tasking, multi-transaction, multi-processor environment.

Today's e-business processing requirements demand completely open standards, full Java compliance, and ActiveX support. Providing efficient Web services means handling over 100,000 hits per day, inquiring against multiple databases for different reasons simultaneously, and doing it all at high speed. Given such performance criteria, UNIX is the only choice.

The NT 4.0 server costs less to support than UNIX and is more suited to smaller scale, regional processing. However, it has limited security, limited disk-clustering capabilities, and its reliability and scalability are challenged. NT's lack of open standards does not encourage serious investment in Web services development, although for those who are willing to wait, Microsoft promises a silver bullet with the release of Windows 2000.

Many network administrators are moving toward a completely TCP/IP network, able to support both UNIX and NT servers. Regardless of the operating system you choose, it's important to consider programming languages up front. Java, C, and C++ allow you to port the application either to UNIX or NT.

Ed McClure,senior vice president, American General Life and Accident:

We use Windows NT as the primary desktop operating system, although UNIX is used under certain conditions. Our primary focus for the selection of an appropriate operating system is its ability to handle the user needs defined. In the case of some data intensive applications, UNIX is the logical choice. However, for most of our users, the ability to use standard Microsoft productivity tools, Lotus Notes applications, and Web-based information is the major requirement, which we believe that NT handles well. In addition, we believe that the majority of purchased software will be available first and supported best in the NT environment. Lastly, recruiting trained staff with NT support and programming skills has, and we believe will continue to be, easier than UNIX

Craig Lowenthal, chief technology officer for financial products, Reliance National:

I would classify Reliance National as a Windows NT shop; while we do have a few UNIX machines, the bulk of our servers are Windows NT. The use of core rating and printing applications running on Windows NT was the primary reason for choosing this path.