Windows Server 2008 is the most recent release of Microsoft’s server line of operating systems.
Windows Server 2008 is the newest Windows Server operating system from Microsoft and is available in a number of business user and data centre focused editions. Designed to help organisations reduce operating costs and increase efficiencies, the Windows Server 2008 platform provides enhanced management control over resources across the enterprise. It is designed to provide better energy efficiency and performance by reducing power consumption and lowering overhead costs. It also helps provide improved branch office capabilities, exciting new remote access experiences, streamlined server management, and expands the Microsoft virtualisation strategy for both client and server computers.
Comparing Small Business Server and Essential Business Server Editions
Small businesses (5 to 50 users) and Medium sized companies (25-250 users) have a choice of two Windows Server 2008 'Business' editions.
Small and Essential Business Server 2008 Brochure

Small Business Server 2008 - Standard and Premium Editions
Windows Small Business Server 2008 is an all-in-one server solution designed to help you keep your data more secure and your company more productive. It provides many of the features used by larger companies, such as e-mail, Internet connectivity, internal Web sites, remote access, support for mobile devices, file and printer sharing, backup, and restore — all at one affordable price
Small Business Server 2008 Datasheet
Small Business Server 2008 Top Ten Reasons
Upgrade Reasons for Small Business Server 2008
Windows Small Business Server 2008 comes in two editions: Standard and Premium. Windows Small Business Server 2008 Premium Edition becomes a second server solution. Windows Small Business Server 2008 Standard Edition will run on one hardware server, and Windows Small Business Server 2008 Premium Edition will run on two hardware servers, with the second server running Windows Server and SQL Server for line-of-business applications.

Windows Essential Business Server 2008 - Standard and Premium Editions
Windows Essential Business Server 2008 is an integrated and affordable solution that offers the Microsoft software that midsize businesses require — preconfigured, integrated, and manageable from a single administrative console, and at a significant discount compared to stand-alone products.
Windows Essential Business Server 2008 Datasheet
Windows Essential Business Server 2008 Top Ten Reasons
Windows Essential Business Server 2008 is available in two editions: Standard and Premium. Standard Edition runs on three separate hardware servers and Premium Edition will run on four.

A Solid Foundation for Your Business
Windows Server 2008 provides a solid foundation for all of your server workload and application requirements while also being easy to deploy and manage. The all new Server Manager provides a unified management console that simplifies and streamlines server setup, configuration, and ongoing management. Windows PowerShell, a new command-line shell, helps enable administrators to automate routine system administration tasks across multiple servers. Windows Deployment Services provides a simplified, highly secure means of rapidly deploying the operating system via network-based installations. And Windows Server 2008 Failover Clustering wizards and full Internet Protocol version 6 (IPv6) support plus consolidated management of Network Load Balancing to make high availability easier to implement, even by IT generalists.
The new Server Core installation option of Windows Server 2008 allows for installation of server roles with only the necessary components and subsystems without a graphical user interface. Fewer roles and features means minimising disk and service footprints while reducing attack surfaces. It also enables your IT staff to specialize according to the server roles they need to support.
Virtualization Built-in
Windows Server Hyper-V, the next-generation hypervisor-based server virtualisation technology, allows you to make the best use of your server hardware investments by consolidating multiple server roles as separate virtual machines running on a single physical machine. You can also efficiently run multiple operating systems - Windows, Linux, and others – in parallel on a single server. With Hyper-V and simple licensing policies, it's now easier than ever to take advantage of the cost savings of virtualisation.
Applications can also be efficiently virtualised using Windows Server 2008 centralised application access technologies. Terminal Services Gateway and Terminal Services RemoteApp allow easy remote access to standard Windows-based programs from anywhere by running them on a terminal server instead of directly on a client computer - without the need for a complicated virtual private network (VPN).
Built for the Web
Windows Server 2008 comes with Internet Information Services 7.0 (IIS 7.0), a Web server and security-enhanced, easy-to-manage platform for developing and reliably hosting Web applications and services. A major enhancement to the Windows Web platform, IIS 7.0 includes a componentized architecture for greater flexibility and control. IIS 7.0 also provides simplified management, powerful diagnostic and troubleshooting capabilities that save time, and comprehensive extensibility.
Internet Information Server IIS 7.0 together with the .NET Framework 3.0 provides a comprehensive platform for building applications that connect users and data, enabling them to visualise, share and act on information. Additionally, IIS 7.0 plays a central role in unifying Microsoft's Web platform technologies—ASP.NET, Windows Communication Foundation Web services, and Windows SharePoint Services.
High Security
Windows Server 2008 is the most secure Windows Server yet. The operating system has been hardened to help protect against failure and several new technologies help prevent unauthorised connections to your networks, servers, data and user accounts. Network Access Protection (NAP) helps ensure that computers that try to connect to your network comply with your organisation's security policy. Technology integration and several enhancements make Active Directory services a potent unified and integrated Identity and Access (IDA) solution. And Read-Only Domain Controller (RODC) and BitLocker Drive Encryption allow you to more securely deploy your AD database at branch office locations.
High Performance Computing
The benefits and cost savings of Windows Server 2008 extend to Windows HPC Server 2008 for your high performance computing (HPC) environment. Windows HPC Server 2008 is built on Windows Server 2008, x64-bit technology and can efficiently scale to thousands of processing cores with out-of-the-box functionality to improve the productivity, and reduce the complexity of your HPC environment. Windows HPC Server 2008 enables broader adoption by providing a rich and integrated end-user experience that scales from the desktop application to the clusters and includes a comprehensive set of deployment, administration, and monitoring tools that are easy to deploy, manage and integrate with your existing infrastructure.