Note, though, that many of the features are the same from one edition to another. They all, for example, include the upgraded Active Directory, remote desktop administration, an encrypting file system, support for removable storage and remote installation.
But other features vary. And, while generally speaking the higher-end versions of the operating systems include all the features of the lower ones, this is not the case in every instance. The best example is the top-of-the-line Datacenter Edition which drops certain features present in some of the lower-rung systems.
So what are these five versions and how do they compare?
It comes with Internet Information Server v.6, ASP.NET and the .NET Framework, features which are also included in the other versions of W2K3. It supports two-way Symmetric MultiProcessing (SMP), 10 inbound server message block (SMB) connections and up to 2GB RAM.
Although it is designed for Web use, it lacks many of the Internet-related features of other versions of the operating system including Internet Authentication Service (IAS), Internet Connection Sharing (ICS), Internet Connection Firewall. It provides Network Load Balancing, but not clustering. Web Edition only has partial support for Virtual Private Network (VPN) connections. Although it can be part of an Active Directory domain, it cannot act as the domain controller.
It provides 2-way and 4-way Symmetric MultiProcessing (SMP) and supports a maximum of 4GB RAM. If used to connect to the Internet, Standard Edition includes a firewall, Virtual Private Network (VPN) support, Internet Connection Sharing (ICS) and Internet authorization services as well as partial support for Public Key Infrastructure (PKI).
Standard Edition comes with a simple built in network load balancer but does not support clustering. Unlike the Web Edition, servers running it can act as Active Directory domain controllers.
The 32-bit version, however, is limited to 32GB RAM, while the 64-bit edition scales up to 64GB. In addition to the features that come with the Standard Edition, the Enterprise Edition also supports Non-Uniform Memory Access (NUMA) Metadirectory Services (MMS), clustering (up to eight nodes) and remote storage. Security features include support for PKI, Kerberos authentication, smart cards and biometrics.
Datacenter Edition is only available preinstalled on a server from approved OEMs: Fujitsu Siemens, Hewlett-Packard, IBM and Unisys for the 32-bit version; H-P, IBM, NEC and Unisys for the 64-bit.
It supports 8-, 16- and 32-way SMP, but not 2- or 4-way, and a maximum of 64GB RAM (32-bit) or 512GB (64-bit). Since it is not designed for edge applications, it does not include a firewall, network bridge or ICS.
Mounting the Siege
While part of Microsoft's motivation for offering an expanded product line may simply be a desire to better serve its existing customers, it also means that it can expand into markets where other operating systems have a stronghold.
At the upper end, its Enterprise and Datacenter versions lay siege to the mission critical servers currently running Unix. To further expand Windows into this area, Microsoft is giving away Windows Services for Unix 3.0, which lets Unix applications run under Windows. It is also creating online training courses to teach Unix developers and administrators the basics of Windows.
On the lower end its Web Edition challenges Linux's domination of that arena. But will it actually eat into either Linux's or Unix's market share, or will existing Windows users simply migrate to it from Windows NT/2000?
"The Web Edition helps Microsoft be more competitive with Linux at the low end," says Tom Bittman, research vice president for Gartner, Inc., based in Stamford, Conn.
But Bittman doesn't feel it is attractive enough to get Linux users to make the switch. Instead he says that most of the Windows Server 2003 sales will come from people replacing their existing hardware running Windows NT 4.0.
"It is a good release with lots of useful enhancements, but it is an incremental release except for Active Directory and IAS," he explains. "Therefore, companies are not going to see an ROI by upgrading to that release outside of their normal hardware refresh cycle."