Microsoft releases test version of energy-saving server program

Microsoft released a test version of a program that lets companies make better use of server computers, an earlier-than-expected debut that steps up competition with VMware. The software, called Hyper-V, is available for customers to download, Microsoft said Thursday in a statement. The test version was expected in 2008. VMware, which this year had the biggest technology initial public offering since Google, has had the market almost entirely to itself for the past six years. Other than Microsoft, emerging rivals include Citrix Systems's XenSource and Virtual Iron Software.