Unix Emulator

UNIX is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs and is currently used to describe any operating system that conforms to UNIX standards, meaning the core operating system operates the same as the original UNIX operating system.
UNIX systems have a graphical user interface (GUI) similar to Microsoft Windows which provides an easy to use environment. However, knowledge of UNIX is required for operations which are not covered by a graphical program and when no Windows interface is available.
The UNIX operating system is made up of three parts; the kernel which is the hub of the system, the shell which acts as an interface between the user and the kernel, and the programs. Types of UNIX OS are Sun Solaris, GNU/Linux, and MacOS X.
An emulator duplicates the functions of one system using a different system, so that the second system behaves like (and appears to be) the first system. The UNIX emulator is a useful learning tool for learning how to use UNIX.

Types of UNIX Emulators

Bochs is a portable PC emulator for UNIX. It can be compiled and used in a variety of modes, some of which are still in development. The typical use of Bochs is to provide complete x86 PC emulation, including the x86 processor, hardware devices, and memory. This allows you to run operating systems and software within the emulator on your workstation, which is like having a machine inside of a machine
Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. It provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment. Thus it is possible to launch Windows applications from the Cygwin environment, as well as to use Cygwin tools and applications within the Windows operating context. With Cygwin, administrators can login remotely to any PC, fix problems within a Posix/Linux/UNIX shell on any Windows machine, and run shell command scripts. Cygwin is supported on Windows 2000, 2003 Server, XP, Vista, and 2008 Server.
MKS Toolkit for Developers is a software package that provides a Unix-like environment for scripting, connectivity and porting UNIX and Linux software to both 32- and 64-bit Microsoft Windows environments with development, testing or system administration tasks. MKS Toolkit dramatically improves the compatibility between Windows and UNIX environments. Providing a comprehensive suite of UNIX and Windows utilities MKS Toolkit for Developers enables developers and system administrators to customize, control, and automate their software development and administrative processes.
UWIN is a computer software package created by David Korn and AT&T Labs. It allows programs written for the operating system UNIX to be run on the Microsoft Windows system with little or no changes. UWIN basically consists of a set of tools and libraries which help application developers compile and run UNIX applications natively on windows.