This may come handy while writing cross-platform scripts.
If you don't want to commit to the idiosyncrasies of a specific shell running on a particular platform, try the Squirrel Shell. The Squirrel Shell provides an advanced, object-oriented scripting language that works equally well on UNIX, Linux, Mac OS X, and Windows systems. Write a script once, and run it anywhere.
Squirrel is a high level imperative/OO programming language, designed to be a light-weight scripting language that fits in the size, memory bandwidth, and real-time requirements of applications like video games.
=> Speaking UNIX: The Squirrel portable shell and scripting language
Cygwin software offers Linux-like environment for Windows making it possible to port software running on POSIX systems (such as Linux, BSD, and Unix systems) to Windows. However, sometime you just wanna run bc or wget under Windows without going through Cygwin. Here are some ports of common GNU utilities to native Win32. In this context, native means the executables do only depend on the Microsoft C-runtime (msvcrt.dll) and not an emulation layer like that provided by Cygwin tools. A must download for die hard gnu folks working on windows systems :)
Download GNU utilities for Windows
Visit offical project to grab common GNU utilities for Windows [binary zip file 3.2M] (Outdated link)
=> Please download latest and updated GNU utilities from GNUWin32 project [thanks Kurt]
Updated for accuracy.