When it comes to virtualization on the Mac, it's mostly discussed in the context of running a variant of Microsoft Windows. This makes sense; the ease of getting Windows to run within OS X (on Intel hardware) is one of the key reasons many first-time Mac buyers are migrating to Apple. However, Windows is hardly the only game in town.
Although the annual proclamations of "the year of the Linux desktop" haven't really panned out, thanks to distributions like Ubuntu, more and more individuals are at least giving Linux a try. Today, Canonical made both the server and desktop versions of Ubuntu 8.10 (codenamed 'Intrepid Ibex') available for download.
Even before the Intel switch, PPC users could effectively run Linux distros on their machines, but virtualization coupled with Intel hardware has made running a VM of Ubuntu -- or any Linux distribution -- fairly painless. Using commercial software like VMware Fusion 2.0 or Parallels Desktop, or open source and free solutions like VirtualBox, you can set up an Ubuntu virtual machine much like you would with Windows.
If you have ever installed a Windows virtual machine, using Parallels, Fusion or VirtualBox, the process for installing Ubuntu is almost exactly the same. Download the Ubuntu 8.10 ISO image (a slow process today with the demand for the new release; it should speed up next week, and there are Bittorrent seeds for faster service) and then select that image for the virtual CD drive when creating your VM. The process, depending on your system, should take under 20 minutes from beginning to end.
Today, I set up a virtual machine of Ubuntu 8.10 in both VMware Fusion 2.0 and VirtualBox 2.04. Parallels Desktop works with Ubuntu, but I had problems trying to get Ubuntu 8.04 installed and am still reading reports of problems with 8.10. Parallels might work just fine with Ubuntu 8.10, but keep in mind that it might be kludgy.
Read on for more install options.