Emulator

From Styleguide

emulator

A piece of software that allows code written for one computer or system to run on another. An emulator is described based on both the hardware it emulates and the hardware it runs on. While there are many NES emulators for Windows, finding a good Mac-based NES emulator is tough.

This process is called emulation. The native code run by the emulator is sometimes referred to as a ROM; this usage is considered jargon.

Emulators are probably best known for facilitating piracy, but there are also valid and legal uses for emulators. Many classic game compilations use emulation to run original code on more recent systems without any noticeable changes in the gameplay experience.

Example: While computer owners can easily download and play classic NES games on an emulator, Nintendo is now offering a legal alternative to this method of reliving your past via its Virtual Console.

Wrong: emulater.

Also see: backward compatible, ROM, Virtual Console.