Microsoft has begun distributing a "feature-complete release candidate" of Microsoft Hyper-V, the hypervisor-based virtualisation software available with versions of Windows Server 2008.

A beta of Hyper-V was included with Windows Server 2008 when it launched last month, and this release candidate provides updated near-final code.

The release candidate features an expanded list of tested and qualified guest operating systems, which now includes Windows Server 2003 Service Pack 2, Novell SuSE Linux Enterprise Server 10, Windows Vista SP1 and Windows XP SP3.

Host server and language support has been expanded to include 64-bit versions of Windows Server 2008 Standard, Enterprise and Datacenter.

English, German and Japanese language options are available, as well as enablement of Hyper-V on international locales. Further language options and support will be available in the final release.

The release candidate also comes with support for more hardware configurations, and offers improved performance and scalability.

It also includes the option for installing Hyper-V Manager Microsoft Management Console on Windows Vista SP1 for remote management.

Bill Hilf, general manager of the Windows Server Division at Microsoft, said: "Virtualisation has been too complicated and expensive for most organisations, which is why less than 10 per cent of servers are virtualised today."

Microsoft said that hardware firms including AMD, Dell, Fujitsu, Fujitsu Siemens Computers, Hitachi, HP, Intel, IBM, NEC and Unisys are working with the firm to test and evaluate Hyper-V.

"Once final code is available, these partners plan to integrate support for Hyper-V into their virtualisation offerings in ways that best fit their business, including pre-installation on servers, device support, solutions and services," Microsoft stated.

The final version of Hyper-V remains "on target" for release by August 2008, Microsoft said.

Customers and partners can download the release candidate at Microsoft's Virtualization and Consolidation website.