VMWare has more features but costs $80, Virtual Box on the other hand is more basic but is free for most users (see Virtual Box licensing FAQ for details). The developer disk images we're going to use are will work with either VMWare Fusion or Sun Virtual Box.
The instructions below include free and legal virtualisation software and Windows disk images. You will need one virtual machine for each version of IE you want to test against.
On an Intel based Mac you can run Windows within a virtual machine. Update: Microsoft now provide virtual machine images for various versions of IE that are ready to use on all of the major OS X virtualisation platforms ( VirtualBox, VMWare Fusion, and Parallels).
