Apple's use of the same Intel chips and other hardware in Macs that PC manufacturers use allows for a number of options when it comes to running Windows-based software. Apple supports the option of dual booting with Boot Camp, and third-party virtualization solutions such as Parallels Desktop and VMware Fusion are available as well. While convenient, all of these options require you to purchase a license for Windows and have Windows running somehow on your system.
Running Windows-based programs from within Windows is by far the stabler and more supported option, but if you do not wish to purchase a license for Windows and still need to run a specific piece of Windows software, then there are alternatives that may get you by.
For nearly a decade the open-source compatibility layer project Wine has been developed for Unix and Linux systems to provide a way to run Windows-based code on these platforms. This is done by providing the various libraries and user interface elements these programs need without having the rest of Windows running in the background. With OS X being a Unix-based operating system, the Wine project and various spinoffs have been ported over to the Mac, and depending on the application can run quite well.
Though a proprietary technology of its own, one Wine-like effort called Cider has been used by game developers like Valve and Electronic Arts to bring numerous PC gaming titles to OS X without having to rewrite as much code. These compatibility layer technologies have the potential to be quite fast, and therefore are a promising option for running various Windows-based programs in OS X without installing Windows itself.
There are a number of Wine projects that can be installed in OS X, and while some of them can take a bit of configuration to set up, a few are geared toward the Mac and can be installed quite easily. These include CrossOver, Wineskin, and WineBottler, of which CrossOver is the only commercial product, the others being free projects.
Since I have used it in the past, I decided to give the latest CrossOver package a try. The program is fairly easy to set up, as the program is packaged in a single application file. You can download a demo version from the CodeWeavers Web site to get started (it offers a 30-day trial). When run, the program will install the necessary components and then allow you to install numerous applications through an installer interface.
If you wish to use commercial programs like Microsoft Office you will need an installation DVD and a license, so since Internet Explorer 7 is freely available I decided to give it a try.
The way Wine works is the Windows executable and its support files are installed in a package called a "bottle." This allows the package to be specifically tailored to run that program, but while it does offer more support for the program it means that many of the resources in the bottle (such as fonts and plug-ins) cannot be used by OS X or by other application bottles. While a limitation, this does allow the entire installed application and its resources to be managed easily, so if you have an installation or configuration problem you can remove all components and start over without affecting other bottles you may have configured.
A number of preconfigured bottles are available through CrossOver's software library and can be downloaded through the CrossOver installer interface.
In the Internet Explorer installation, numerous Windows fonts, ActiveX control frameworks, and Microsoft XML parsers were installed in the bottle. Once the installation was complete, double-clicking the Internet Explorer icon launched the program and we were up and running. The interface does not look as pretty (or ugly, depending on your perspective) as Windows, but it runs.
While CrossOver is one option, if you prefer not to purchase a license you can try running the other Wine distributions. Additionally, if you choose to use a Wine distribution for running Windows applications be aware that there may be more bugs and stability issues than with Boot Camp or a virtualization solution like Parallels or VMware Fusion.