Windows: A family of operating systems for personal computers, Windows dominates the personal computer world, running, by some estimates, on 90% of all personal computers. Like the Macintosh operating environment, Windows provides a graphical user interface (GUI), virtual memory management, multitasking, and support for many peripheral devices. In addition to Windows 3.x and Windows 95, which run on Intel -based machines, Microsoft also sells Windows NT, a more advanced operating system that runs on a variety of hardware platforms. Windows CE: Windows CE is a version of the Windows operating system designed for small devices such as personal digital assistants (PDAs) (or Handheld PCs in the Microsoft vernacular). The Windows CE graphical user interface (GUI) is very similar to Windows 95 so devices running Windows CE should be easy to operate for anyone familiar with Windows 95. Windows 98: The heir apparent to Windows 95, Windows 95 was released in mid-1998. Originally it was called Memphis, and then Windows 97, but Microsoft changed the name when it realized that it was going to miss its target 1997 release date. Windows 98 offers support for a number of new technologies, including FAT32, AGP, MMX, USB, DVD and ACPI. Its most visible feature, though, is the Active Desktop, which internet explorer with the operating system. From the user's point of view, there is no difference between accessing a document residing locally on the user's hard disk or on a web server halfway around the world. Windows NT: The most advanced version of the Windows operating system, Windows NT is a 32-bit operating system that supports preemptive multitasking. There are actually two versions of Windows NT: Windows NT Server, designed to act as a server in networks, and Windows NT Workstation for stand-alone or client workstations. Windows 2000: Windows 2000 is the name given to the next version of Microsoft's line of operating systems, formerly know as Windows NT 5.0. In the future, the core code of NT will serve as the basis for all of Microsoft's PC operating systems--from consumer PCs to the highest performance servers. In fact, the next major release for consumers to follow Windows 98 will be based on the Windows NT code base. This name will encompass all future business and consumer releases of Windows. Windows 2000 Professional: Windows 2000 Professional will be Microsoft's mainstream desktop operating system for businesses of all sizes, replacing Windows NT Workstation 4.0, which many people are using today as the standard business desktop. Windows 2000 Professional will deliver the easiest Windows yet, the highest level of security, state-of-the-art features for mobile users, industrial-strength reliability, and better performance while lowering the total cost of ownership through improved manageability. Windows 2000 Server: Windows 2000 Server will offer industry-leading functionality and support new systems with up to two-way symmetric multi-processing (SMP). Ideal for small to medium enterprise application deployments, Web servers, workgroups, and branch offices, this version of Windows 2000 is expected to be the most popular server version. Existing Windows NT Server 4.0 systems with up to four-way SMP can be upgraded to this product. Windows 2000 Advanced Server: Windows 2000 Advanced Server will be a more powerful departmental and application server, also providing rich network operating system (NOS) and Internet services. Supporting new systems with up to four-way SMP, and/or large physical memories, this new product offering will be ideal for database-intensive work, and will integrate clustering and load balancing support to provide excellent system and application availability. Existing Windows NT 4.0 Enterprise Edition servers with up to eight-way SMP can install this product, which will be priced below today's Windows NT Server Enterprise Edition product. Windows 2000 Datacenter Server: Windows 2000 Datacenter Server will be the most powerful and functional server operating system ever offered by Microsoft. It supports up to 16-way SMP and up to 64GB of physical memory (depending on system architecture). Like Windows 2000 Advanced Server, it will provide both clustering and load balancing services as standard features. It is optimized for large data warehouses, econometric analysis, large-scale simulations in science and engineering, OLTP, and server consolidation projects. Windows XP: An upgraded client version of Windows 2000, Windows XP provides numerous changes to the user interface, including the Start menu, Taskbar and control panels. XP adds improved support for gaming, digital photography, instant messaging and wireless networking. XP Home Edition is designed for the consumer, and XP Professional is aimed at the office worker with added security and administrative options. XP supports the ClearType display technology for improved sharpness on LCD screens. Internet enhancements include Internet Explorer 6, improved connection sharing and a built-in firewall. A 64-bit version is also provided. Originally code named Whistler, Windows XP is .NET enabled. UNIX: UNIX is a multiuser, multitasking operating system that is widely used as the master control program in workstations and especially servers. A myriad of commercial applications run on UNIX servers, and most Web sites run under UNIX. There are many versions of UNIX, and, except for the PC world, where Windows dominates, almost every hardware vendor offers it either as its primary or secondary operating system. UNIX is written in C. Linux: A version of UNIX that runs on a variety of hardware platforms including x86 PCs, Alpha, PowerPC and IBM's product line. Linux is open source software, which is freely available; however, the full distribution of Linux along with technical support and training are available for a fee from vendors such as Red Hat Software and Caldera. Due to its stability, Linux has gained popularity with ISPs as the OS for hosting Web servers. Solaris: Solaris is a multitasking, multiprocessing operating system and distributed computing environment for Sun's SPARC computers from SunSoft. It provides an enterprise-wide UNIX environment that can manage up to 40,000 nodes from one central station. Solaris is known for its robustness and scalability, which is expected in UNIX-based SMP systems. An x86 version of Solaris is available that can also run applications written for Sun's Interactive UNIX.