Unlike hypervisor-based forms of virtualization, Virtuozzo creates virtual environments on top of a single base operating system instance, and in that limitation lies Virtuozzo's strength. "That's not only OK, but is actually preferable for some uses, as it simplifies patches and uses fewer server resources," wrote one judge. As such, it's no surprise to find Virtuozzo and its open source cousin OpenVZ, as the foundation of many large-scale Linux-based hosting environments.

With its success in the marketplace, judges viewed enhancements to the latest version of Virtuozzo as "evolutionary, not revolutionary." With version 4.0, Virtuozzo management tools can now display, organize and manage servers according to either physical or logical characteristics or group servers as a unit. Also lauded were enhancements to Virtuozzo's backup model, and enhanced high-availability functions like support for Red Hat clustering. A starter pack includes a license for either single or dual CPU servers and up to four virtual environments, full management tools and one year of Silver support, and it lists for $1,198.