As always, I'm typing this message out on my Apple iMac. But with a BIG difference: I'm typing it out in Ubuntu Linux, running side-by-side with Mac OS X Tiger. How can this be? I'm using a new program named Fusion by VMware, one of the first of the new-technology virtualization software products avaialble for Intel-based Macs. 
Before virtualization, there was emulation: Back when Macs used IBM/Motorola (Freescale) PowerPC processors, Connectix (and later Microsoft) sold a product named Virtual PC for many years. Virtual PC allowed people to run Windows on a PowerPC Mac, but it was extremely slow, and it was buggy. The problem was because the PowerPC processor had to emulate an x86 processor and could not run x86 code without exhibiting a huge performance slowdown.
However, Apple has since switched to Intel Core processors. And with the switch came a new technology from Intel called Intel Virtualization Technology (VT). Simply put, VT allows computers to run more than one operating system at once, without a large decrease in performance. Each virtual machine only consumes system resources when you actually use it, so having 5 virtual macines but using none won't impact performance. You can use the same peripherals (keyboards, mice, printers) that you use on the Mac side, so you don't have to buy extra hardware. And you can also make several "virtual machines" on your hard drive, so you can run Windows XP/Vista/2000, many flavors of Linux, FreeBSD, or even (barf) Windows ME. (Warning: Install Windows ME only if you are willing to deal with untreatable pain and suffering.)
Virtual machines are good for many uses: If you want to switch to a Mac for most of your work, but use certain business software that only runs on the Windows or Linux platforms, a virtual machine is a good idea. Same goes for if you have a Mac and constantly have to use non-standards compliant websites that still require Microsoft Internet Explorer and/or ActiveX controls (neither of which, fortunately, exist for the Mac). Virtual machines are not very good for gaming, though... it's about the only place left in the computer world where a dedicated Windows PC (or a game console) is still the best choice.
As always, if you plan on using Windows with a virtual machine, make sure you use good antivirus and antispyware software like you would with a normal Windows PC.
Currently, two excellent virtualization products exist for the Mac: A start-up called Parallels was the first to come out with a virtualization product for the Mac in 2006, and it has been further refined and enhanced since. More recently, VMware (who has made Windows and Unix virtualization products for years) launched their own Mac virtualization product called Fusion, which is a bit speedier... I'm using Fusion for the virtual machines on my Mac. Both cost $79 in addition to the Intel-based Mac and the copy of Windows (if you so choose)... not too bad. And remember, if you want to go the Linux route with your virtual machines, Linux distributions are almost always free.
So, if you own an Intel-based Mac or are considering switching to one, consider getting some virtualization software. It may remove the only obstacle that's holding you back...
Before virtualization, there was emulation: Back when Macs used IBM/Motorola (Freescale) PowerPC processors, Connectix (and later Microsoft) sold a product named Virtual PC for many years. Virtual PC allowed people to run Windows on a PowerPC Mac, but it was extremely slow, and it was buggy. The problem was because the PowerPC processor had to emulate an x86 processor and could not run x86 code without exhibiting a huge performance slowdown.
However, Apple has since switched to Intel Core processors. And with the switch came a new technology from Intel called Intel Virtualization Technology (VT). Simply put, VT allows computers to run more than one operating system at once, without a large decrease in performance. Each virtual machine only consumes system resources when you actually use it, so having 5 virtual macines but using none won't impact performance. You can use the same peripherals (keyboards, mice, printers) that you use on the Mac side, so you don't have to buy extra hardware. And you can also make several "virtual machines" on your hard drive, so you can run Windows XP/Vista/2000, many flavors of Linux, FreeBSD, or even (barf) Windows ME. (Warning: Install Windows ME only if you are willing to deal with untreatable pain and suffering.)
Virtual machines are good for many uses: If you want to switch to a Mac for most of your work, but use certain business software that only runs on the Windows or Linux platforms, a virtual machine is a good idea. Same goes for if you have a Mac and constantly have to use non-standards compliant websites that still require Microsoft Internet Explorer and/or ActiveX controls (neither of which, fortunately, exist for the Mac). Virtual machines are not very good for gaming, though... it's about the only place left in the computer world where a dedicated Windows PC (or a game console) is still the best choice.
As always, if you plan on using Windows with a virtual machine, make sure you use good antivirus and antispyware software like you would with a normal Windows PC.
Currently, two excellent virtualization products exist for the Mac: A start-up called Parallels was the first to come out with a virtualization product for the Mac in 2006, and it has been further refined and enhanced since. More recently, VMware (who has made Windows and Unix virtualization products for years) launched their own Mac virtualization product called Fusion, which is a bit speedier... I'm using Fusion for the virtual machines on my Mac. Both cost $79 in addition to the Intel-based Mac and the copy of Windows (if you so choose)... not too bad. And remember, if you want to go the Linux route with your virtual machines, Linux distributions are almost always free.
So, if you own an Intel-based Mac or are considering switching to one, consider getting some virtualization software. It may remove the only obstacle that's holding you back...
