Its simple really. It's all about cost. Virtualization technology allows the software industry and it's cousins (web design, eCommerce, internet publishing and so forth) the distinct ability to quickly prototype, develop, test and deploy content quickly without the immediate need for expensive hardware and complex client server environments.

 Today it's possible to download a pre-built virtual appliance that is configured for many of the typical needs faced by developers. In my own work, I frequently make use of Ubuntu Linux based web server appliances from VMWare. Once launched in the free VMWare player, the server runs virtually on your local machine. It is then possible to configure and use this server for localized testing of web applications. It's a matter of loading and configuring the proper libraries, databases and web server components necessary to launch and run the application. Testing is identical to the process used against physical servers. Because the virtual applicance is really a set of files, it's easy to make backup copies and move entire virtual appliances to the VWWare server.

The other significant area for virtualization is in the creation of specialized devices dedicated to specific transactions or data processes. I recently created a series of specialized web servers that connected some internal web applications to our backend business intelligence platform. The web services and SDK elements required by this process could have interferred with other libraries in a multi-application environment. By creating a customized, small appliance, I was able to avoid the expensive and risky need to coordinate deployment and testing activities. The appliances are also easy to replicate and backup. Disaster recovery is a much simpler exercise.

The natural extension of this process is to virtualize the desktop. Again, in my own professional life, I've found it expedient to create multiple desktop environments for different types of application development and testing. I have a Windows XP virtual desktop with Visual Studio 2008 installed and an Ubuntu Linux platform with the latest Java and Eclipse development environments.

Virtualization is not without it's cost. The host hardware needs to be robust, especially in desktop emulation. The benefits, however, are significant in both direct expense and, more importantly, time to develop.