The most prominent names in open source descend on Boston this week for the annual LinuxWorld Conference and Expo. Highlights of the show will include a new Mobile and Embedded conference track and a Grid Solution Showcase, but the hottest trend seems to be virtualization, with several new offerings set to debut throughout the week.

XenSource, which markets commercial products based on the open source Xen virtualization software, is expected to introduce XenEnterprise, a proprietary solution that can virtualize any x86 OS, including Windows, in addition to OSes that have been custom modified for Xen. The new product ships with management tools and requires virtualization-enabled processors from AMD or Intel to run unmodified OSes.

Virtual Iron, expected to announce Version 3.0 of its virtual infrastructure software at the show, is also putting its weight behind Xen. As does XenEnterprise, the new release will support Intel VT and AMD Pacifica-enabled processors to allow virtualization of Windows and other unmodified operating systems. Rounding out the offering is Virtual Iron’s policy-based Virtualization Manager, which provides a central console for monitoring and automating virtual resources.

Many industry analysts see Xen as tough competition for VMware, which markets its own line of products based on a proprietary virtualization engine. VMware’s recent decision to release its entry-level VMware Server product free of charge could be construed as an attempt to counter the momentum of its open source competitor. At LinuxWorld, VMware is expected to open its product line even further, by making its virtual machine disk format available to developers “without royalty, restriction, or license.” This move should allow a wider range of developers to join companies such as Altiris, BMC, IBM, and Symantec in building add-on products that work with VMware.