Emulator is a software tool that runs on a PC platform as an application in the host environment.
In theory this allows existing PDP-11 operating system environments and standalone custom applications to run on new platforms under new host environments. Emulator' programs have been initiated by various interests and engineering groups. While some of these emulators have been successful in achieving specific goals, others have have been considerably less successful on many fronts. Because emulation requires a high level of microprocessing this approach has only recently become viable through the development of today's ever faster PC processors. As the performance of these processors improves so too does the performance of software that is reliant upon them.