VMware produces virtualization software for x86-compatible computers. It is probably the world's leading virtualization software development company. Sometimes consumers even think that virtualization is equal to VMWare. Probably because the "VM" in company's name is an acronym of "Virtual Machine".

VMware produces servers and desktop software. Its desktop version runs on Windows, Linux, and Mac OS X.

The company also have an enterprise class virtualization technology - VMware ESX Server - that runs on physical server without any underlying OS.

The products of VMWare are popual as "Virtual Machines", "Virtual Dedicated Servers" because it are based on a virtualization method that provides a complete simulation of the underlying hardware.

VMware's software platform creates a fully virtualized set of hardware to the guest OS. WMware virtualizes the hardware for a video adapter, a network adapter, and HDD adapters. The host provides pass-through drivers for guest USB, serial, and parallel devices. This makes VMware's virtual machines highly portable between computers, because every host looks nearly identical to the guest.

This means that any administrator can pause operations on a VM guest, to move or copy that guest to another physical machine, and there resume execution exactly at the point of suspension. Alternately, for enterprise servers, a feature called VMotion allows the migration of operational guest VM between different computers that share the same storage.

VMware's ESX Server takes a more optimized path to running target OS on the host than emulators which simulate the function of each CPU instruction on the target machine one-by-one, or dynamic recompilation which compiles blocks of machine-instructions the first time they execute, and then uses the translated code directly when the code runs subsequently.

VMware technology doesn't emulate an instruction set for different hardware not physically present. This significantly boosts performance, but can cause problems when moving VM guests between hardware hosts using different instruction-sets, or between hardware hosts with a differing number of CPUs.

The virtualization method of VMware uses the CPU to run code directly whenever possible. When direct execution cannot operate, such as with kernel-level and real-mode code, the software re-writes the code dynamically, a process that VMware calls "binary translation" (BT). The translated code gets stored in spare memory, typically at the end of the address space, which segmentation mechanisms can protect and make invisible.

This makes VMware's virtualization technology to operate faster than emulators, running at more than 80% of the speed that the virtual guest operating-system would run directly on the same hardware. VMware claims an overhead between 3% and 6% for computationally-intensive applications.