The virtualization software layer managing hardware requests from a guest OS, simulating answers from a real hardware. Mistakenly used as Hypervisor synonymous.

See virtual machine monitor.

Virtual Machine Manager. The 32-bit code loaded before Windows that also manages most low-level drivers in Windows and Windows95. It consists of a number of linked VxD's, and may or may not incorporate other VxD's from separate files (at boot time in Win31, also at run time in Win95).

VISSR Multiplexor/Modulator Watts