This week, Microsoft revealed that its upcoming Windows Server 2008-based midsized business server solution, code-named Centro, has been given a final name: The product will be sold as Windows Essential Business Server when it hits the market in the second half of 2008.

Windows Essential Business Server is currently in a limited private beta, but will be expanded to a wider public audience in early 2008, Microsoft says. The logistics, however, are somewhat daunting: To install Windows Essential Business Server, you'll need three or four 64-bit servers, depending on the version you purchase: The Standard edition includes a management server with Windows Server 2008 and System Center Essentials, a messaging server with Exchange Server 2007 and Forefront Security for Exchange, and a security server with the next version of Microsoft ISA Server and an Exchange 2007 gateway. The Premium edition includes these servers, as well as a fourth database server with SQL Server 2008.

Eric Watson, a group program manager on the Centro team, told me this week that the product is targeted at the businesses that fall between traditional small businesses and large enterprises. These midmarket businesses typically have 25 to 250 PCs, 50 to 1000 employees, and 1 to 5 IT administrators. It's a market that has been underserved to date by computing infrastructure products and services.

"IT administrators in mid-sized businesses are overwhelmed today, and overworked," Watson says. "They spend most of their time fighting fires and being reactive. Windows Essential Business Server will help them become proactive and take advantage of new technology."

The key to Windows Essential Business Server is its integrated setup sequence and centralized management console, both of which are designed to overcome the complexity of working with multiple physical servers. The product will be sold as complete solutions from server makers and in a software-only package that administrators can install on their hardware. Companies such as Fujitsu, Intel, HP, and IBM have already signed on to sell unique Windows Essential Business Server-based solutions, and Microsoft says other partners will be announced in the coming months.

Less well known is Cougar, the code name for Microsoft's next version of Windows Small Business Server. Like Windows Essential Business Server, this product is based on Windows Server 2008 and will likely ship within a year.