Claim: Windows Essential Business Server 2008, was Microsoft's server offering for mid-size businesses (up to a maximum of 300 Users and/or Devices), and it was built in  the Windows Server 2008 codebase, two editions are available: Standard and Premium, where the Standard edition includes three Windows Server 2008 x64 Standard Servers and on top of those three servers: Microsoft Exchange 2007, Microsoft System Center Essentials, Microsoft Forefront Security for Exchange Server, and Forefront Threat Management Gateway (Medium Business Edition).
Evidence: Windows Essential Business Server 2008 (code named Centro) was Microsoft's server offering for mid-size businesses (up to a maximum of 300 Users and/or Devices). Built from the Windows Server 2008 codebase, two editions are available: Standard and Premium. The Standard edition includes three Windows Server 2008 x64 Standard Servers and on top of those three servers: Microsoft Exchange 2007, Microsoft System Center Essentials, Microsoft Forefront Security for Exchange Server, and Forefront Threat Management Gateway (Medium Business Edition). The Premium edition adds another Windows Server 2008 Standard Edition and the Microsoft SQL Server 2008 Standard database software.