There are three simple packages that provide a unix-like environment under Microsoft Windows: SFU, Cygwin, and uwin. There is also a relatively new player called colinux. A new product is available from VMWARE for free called VMware Server.

SFU:

Microsoft Services For Unix used to be a product, but as of this particular writing, it's a free download. It comes with pdksh and tcsh.

Cygwin:
Cygwin is also free. It comes with bash and many other gnu packages. It uses bash. The Cygwin : //www. cygwin. com> tools are ports of the popular GNU development tools for Windows 9x/ME/NT/2000

uwin:
uwin was written by ATT and it also is free.

Colinux:
Cooperative Linux is the first working free and open source method for optimally running Linux on Microsoft Windows natively. More generally, Cooperative Linux (short-named coLinux) is a port of the Linux kernel that allows it to run cooperatively alongside another operating system on a single machine.

VMware Server:

VMware Server is a product for server virtualization. Vmware Server enables you to partition a Physical Server into multiple virtual machines. You can run Windows and Linux operating systems and applications on the same physical server, at the same time.

CoreUtils:
The GNU Core Utilities are the Basic file, shell and text manipulation utilities of the GNU operating system

Vim:
This "vi" is intended for those who wish to master and advance their skills above the basic features of the basic editor. It covers buffers, "vi" command line instructions, interfacing with UNIX commands, and ctags. The vim editor is an improved version of vi. Vim is available for many different systems and there are several versions.