It hardly seems possible that Windows Server 2003 is already four years old and about to be replaced by Longhorn Server. Four years is a long time in the computer industry, and Microsoft has used that time to add a plethora of important features to Longhorn Server. Here's my list of Longhorn Server's 10 most important new features and enhancements.

10. Hypervisor-based virtualization—Microsoft has found a way to incorporate virtualization—one of the hottest technologies in IT—into the Windows OS. Hypervisor support will let Longhorn Server take advantage of the virtualization capabilities of the new generation of Intel and AMD processors. The result is improved performance for virtual machines and no need for additional virtualization software.

9. New backup and recovery tools—Longhorn Server's backup and restore technology is a welcome change for Windows 2003 and Windows 2000 Server administrators struggling with the old, hard-to-use NTBackup. Longhorn Server uses Microsoft Volume Shadow Copy Service (VSS) to perform block-level backups and can also back up to DVD.

8. Updated Windows Firewall—Like Windows Vista, Longhorn Server will include the updated Windows Firewall. The new version lets you filter both incoming and outgoing traffic and can be configured using Group Policy or Microsoft Management Console 3.0.

7. Windows SharePoint Services 3.0—Longhorn Server will include Windows SharePoint Services3.0, which features an updated administration model that lets you delegate SharePoint administrative tasks. SharePoint Services 3.0 also provides a multistage recycle bin and support for VSS for improved recoverability.

6. IIS 7.0—Microsoft Internet Information Services (IIS) 7.0 has a new modular architecture that provides more granular control over which features are installed on the Web server. IIS 7.0 also sports an administration UI that lets you manage both Web server and ASP.NET properties. Editing and backing up configuration data is easy because IIS 7.0's configuration settings are stored in an XML file.

5. New Server Manager—Acting like a combination of the Windows 2003 Manage Your Server Wizard and the Security Configuration Wizard, Longhorn Server's Server Manager provides a role-based management interface. Server Manager lets you add and change server roles and features, monitor server health, and manage user accounts and services.

4. WDS—Longhorn Server revamps Microsoft Remote Installation Services and renames it Windows Deployment Services (WDS). WDS supports Microsoft's new image-based deployment using the Windows Imaging Format. WDS is built using Windows Preinstallation Environment and supports bare-metal and network installations for Vista and Longhorn Server.

3. Enhanced Terminal Services—Based on the new RDP 6.0, Terminal Services support in Longhorn Server lets users share a single remote application rather than an entire desktop. From the remote system's perspective, using Terminal Services to run an application looks just like executing a local application. For example, you can start remote programs by double-clicking an icon, menu option, or associated file extension.

2. NAP—The long-awaited Network Access Protection (NAP) security feature lets you create a customized health policy that a networked client must comply with before being granted network access. For example, you might require the client to have antivirus software, specific firewall settings, and certain updates to software. Clients that don't comply will have restricted network access until the problems that cause them to be noncompliant are corrected.

1. Server Core—Longhorn Server's biggest enhancement is a new type of server installation called the Server Core. The Server Core doesn't provide a graphical UI, requiring system configuration and management to be performed either through the command line or remotely, and doesn't include application-oriented features such as the Microsoft .NET Framework or Microsoft Internet Explorer. The Server Core can act as a domain controller, a DNS server, a DHCP server, or a file server.