Wine (Wine Is Not an Emulator) is an open source implementation of the Windows API which aims to allow Linux / Unix-like systems to execute programs written for Microsoft Windows. It does not require Microsoft Windows, but can use native Windows DLLs if they are available. It provides both a development toolkit for porting Windows source code to Unix as well as a program loader, allowing many unmodified Windows programs to run on x86-based Unixes. You can easily run MS-Office, Photoshop, IE browser and selected games under Wine software.
Finally, after 12 years of development, version 1.0 was released today i.e. June 17, 2008 under GPL License.
=> Visit wine project website to grab version 1.0.