Charon-PAR is a hardware virtualization layer running under Linux on industry standard servers. It emulates a range of historic PA-RISC HP3000 and HP9000 hardware and allows existing users of such systems to move to modern Intel-based server hardware.
Modern software operating systems contain a hardware abstraction layer (HAL). The HAL creates a software layer on top of the hardware to "virtualize" the functionality of the hardware components. The Charon-PAR products are essentially HALs of complete legacy hardware, including its PCI-based I/O devices. They are precise models of the legacy hardware, and contain modules which emulate the legacy hardware CPUs, console subsystem, buses and I/O adapters, disks and tapes.
The installation of Charon-PAR on a general purpose host platform provides an exact model of the historic HP3000 or HP9000 hardware. On this 'virtual' system you install your legacy operating system and the associated applications, just as though you were using the original hardware. In most cases, no changes of the software are required. The Charon-PAR emulated systems run the same binary code and the same I/O drivers as the original hardware. This is illustrated in the following image: