Charon is the brand name of a group of software-products able to emulate several CPU-architectures, especially with respect to now given legacy-platforms of the large former computer-manufacturer and industrial computing-, data-handling and information-processing company Digital Equipment Corporation, shorted known as just DEC.
Thus, the given emulators available under this brand, are used to cover primarily Digital’s own former DEC-hardware platforms, which are still in use today despite its age, such as PDP-11, VAX, and AlphaServer – These support many of DEC's legacy operating-systems, including Tru64 Unix and OpenVMS.
They run on Microsoft Windows, Linux or VMware ESXi and provide a virtual PDP-11, VAX, AlphaServer, HP 3000, and SPARC environment.
[1] In ancient Greece, Charon was the ferry man, whose task was to transport the dead across the river called Styx to Hades.
The Stromasys emulator provides virtualization of the old DEC hardware allowing old operating systems such as OpenVMS to continue working without change.