VMware markets two virtualization products for servers:
- VMware ESX (formerly called "ESX Server"), an enterprise-level product, can deliver greater performance than the freeware VMware Server, due to lower system overhead. VMware ESX is a "bare-metal" product, running directly on the server hardware, allowing virtual servers to also use hardware more or less directly. In addition, VMware ESX integrates into VMware vCenter, which offers extra services to enhance the reliability and manageability of a server deployment, such as
- VMotion - the capability to move a running virtual machine from one ESX host to another
- Storage VMotion - the capability to move a running virtual machine from one storage device to another
- DRS - Dynamic Resource Scheduler - automatic load balancing of a ESX cluster using VMotion
- HA - High Availibility - In case of hardware failure in a cluster, the virtual severs will automatically restart on another host in the cluster
VMware ESX Server is virtual infrastructure software for partitioning, consolidating and managing servers in mission-critical environments. Ideally suited for enterprise data centers, ESX Server minimizes the total cost of ownership of computing infrastructure by increasing resource utilization and its hardware-independent virtual machines encapsulated in easy to-manage files maximize administration flexibility.
- VMware ESXi (formerly called "VMware ESX 3i"), is quite similar to ESX, but differentiates in that the Service Console is removed, and replaced with a minimal BusyBox installation. Disk space requirements are much lower than for ESX and the memory footprint is reduced. ESXi is intended to be run from flash disks in servers but can be run from normal disks. VMware ESXi hosts can't be managed directly from the console, all management is performed through a VirtualCenter Server. In July 2008, VMware decided to give ESXi away for free.
- VMware Server (formerly called "GSX Server") is also provided as freeware, like VMware Player, but it is possible to create virtual machines with it. It is a "hosted" application, which runs within an existing Linux or Windows operating system.