Microsoft has made a 'release candidate' version of its server virtualisation software, Hyper-V, generally available.

Hyper-V is Microsoft's rival offering to VMware's server virtualisation technology, and promises to improve the utilisation rates and cost-effectiveness of organisations' commodity server estate.

"Hyper-V will help customers consolidate IT systems and allow their businesses to respond more rapidly to ever-changing market conditions,” said Bill Hilf, general manager of the Windows Server Division

The release of Hyper-V adds to the cutthroat competition in the server virtualisation market, noted Gartner analyst Thomas Bittman, in a recent research note. He suggested that "VMware is the most-mature solution with the richest management portfolio".

Bittman also said that Microsoft may initially struggle to match competitors such as VMware, Citrix and Oracle. Gartner is "concerned that the Hyper-V architecture may cause reliability, vulnerability and maintenance issues because of its dependency on a single copy of Windows Server 2008," he added.

But Bittman suggested that Microsoft's main opportunity for Hyper-V was in the mid-market.

The Hyper-V release candidate features an expanded list of tested and qualified guest operating systems, including: Windows Server 2003 Service Pack 2; Novell SUSE Linux Enterprise Server 10; Windows Vista SP1; and Windows XP SP3.