Windows Server 2008 is the server operating system developed by Microsoft. It is considered the successor to Windows Server 2003 and boasts new features such as Server Core, an optional installation which allows administration completely via the command-line interface.
In Windows Server 2008, Microsoft rolled together the Manage Your Server and Security Configuration Wizard from Windows Server 2003 into the Server Manager console, which allows administrators to conduct many server tasks.
Active Directory received a major update in Windows Server 2008, with expanded Group Policy and identity management features. Other updates include Active Directory Rights Management Services and Federation Services.
The server software also has Failover Clustering, which promises high-availability for mission-critical tasks.