Recently I had to review a product which was being offered as a Virtual Appliance. This was the first time I had come across something like this. Pretty soon I was "googling" around to understand this better.

A virtual appliance is a pre-built, pre-configured virtual machine that has an OS, the application and other supporting software all packaged together and ready to go. All you do is to use a product such as VMWare Fusion/Player or Sun VirtualBox to play the appliance and viola you have a running product. I downloaded a Wordpress Virtual Appliance from http://www.turnkeylinux.org/wordpress. Turnkey has many other appliances at http://www.turnkeylinux.org/
I have both VMWare Fusion and Sun VirtualBox on my Mac. Next I either open the appliance in VMWare or Import the appliance in VirtualBox. In a few minutes I had the VM ready and the Wordpress application working like a champ. In my excitement to play with this toy i installed appliances for bugzilla and drupal. The simplicity of this is what amazed me.

I find this approach of delivering software very innovative. It drastically simplifies the administrative tasks required to setup an application. I do not know how efficient this modal is in real work use, but frankly I don't care its just too elegant.

Too learn more about Virtual Appliances check http://www.vmware.com/appliances/getting-started/learn/overview.html