Virtual Machine softwares like VMWare were started as just software allowing users to boot up different OSes (if they have the processors and RAMs to handle the additional load) for working with them simultaneously. However the use of virtual systems will be much more expansive in the future. And what more can you say, when the media treats it as the best feature of 10.
[CNET] Solaris Containers, a form of operating system virtualization technology that offers most of the advantages of multiple separate virtual operating system images while maintaining a single image to manage. Containers create a private, isolated execution space for each application within the context of a single master operating system instance, each with its own local variables and proxy copies of global variables, IP address, security permissions, file system view and so on. Sun claims that in addition to being lightweight in terms of resource overhead, containers are also extremely dynamic, capable of being created in under 10 seconds. Resource allocation is granular, in single-digit percentages of CPU, physical memory and I/O. Containers are managed by the Solaris Container Manager, which creates and deletes containers and defines container resource policies.
[OS News] Containers are an emerging technology of mammoth proportions. Sun did not promote the containers as much as they could have. This is an extremely important technology as it provides isolation, increased utilization of resources and speedy environment restart, cloning, and other cool features with very little overhead – unlike VMWare and other emulation environments.