A few years ago, all it took for an operating system to gain acceptance was an inexpensive hardware platform and a good application base. Now more complex factors come to bear: How easy it is to use and to develop applications for? How stable is its technology base? Driving this change is the trend among businesses to downsize. These companies are abandoning their minicomputers and mainframes for networked desktop systems. The personal computer is proving itself capable of handling mission-critical tasks, but the corporate customer wants more.
The sophisticated operating systems of mainframes and minicomputers (e.g., DEC's VMS or IBM's MVS) support multitasking, virtual memory, security, robust file systems, and efficient system administration. All these features are incorporated into each of the desktop-based operating systems discussed in this State of the Art section. These operating systems -- Microsoft's Windows NT, IBM's OS/2 2.0, Apple's System 7.0, Univel's UnixWare, Next's NextStep, and SunSoft's Solaris -- combine the best of the mainframe/minicomputer world with the best of the desktop world. The result is a relatively bulletproof system designed to be implemented on a large scale and able to run familiar desktop applications with a familiar user interface.
In competing for the corporate customer, hardware has become a commodity, and the operating system has become the vehicle for the competition. The latest manifestation of how the operating system is the focus of the competition for the corporate customer is found in Microsoft's Windows.
The Server Is the Key
Windows covers a wide range of systems, from notebooks and pen-based computers to the desktop. Originally, Windows was intended to make it easier for people to use the PC, but recently, it has expanded its mission: to form the foundation for a better server in client/server computing through NT. Mike Nash, NT marketing manager for Intel, describes the operating systemas "kind of a best-of package. If you name all the things you would want out of Unix, VMS, OS/2, DOS, and Windows, you will find they're all in NT." If it sounds like it's being developed as an ideal operating system for the server, that's because it is. All the serious operating-system contenders are vying to succeed in the corporate market by capturing the server.
The server is a key to operating-system marketing strategies because corporate networks are typically made up of a mix of clients: Accounting might use PCs while the marketing staff has Macs and the engineering department uses Unixbased workstations. That mix is slow to change because existing equipment and their applications tend to be preserved whenever possible. So, the developer has a better chance supplying operating systems on servers and letting the operating system's performance speak for its usefulness on new client machines. Witness the multiplatform support adopted by operating-system developers.