VMware, an EMC subsidiary whose software lets multiple operating systems run on the same computer, is expected to announce next week that it will begin giving away one of its key products for free, CNET News.com has learned. The company sells three core products, VMware Workstation, GSX Server and ESX Server, but competition is on the horizon in a market VMware once had to itself. On Monday, however, the company is expected to announce it will give away GSX for free, sources familiar with the plan said. First in line is the open-source Xen effort that will become part of the two major commercial versions of Linux: Red Hat Enterprise Linux and Novell's Suse Linux Enterprise Server. In addition, Microsoft is working on similar software it plans to add to its next server operating system, called "Longhorn Server." Others such as Virtual Iron and SWsoft's Virtuozzo have technology that overlaps.