As virtualization continues to permeate IT shops, many independent software vendors (ISVs) are distributing software as Linux virtual appliances: preconfigured virtual machines that include the application's entire stack, including the operating system. But industry experts say that end users need to understand the design of these virtual appliances before bringing them into an environment.

Virtual machines are virtually taking over the world. By itself a virtual machine is just a container that describes various resources such as memory, disk space, processor, and network card, and allocates them from a physical machine. As with a physical machine, it's the software bits (the operating system and applications) that make a virtual machine usable.

Yankee Group has said that virtual appliances will enable the delivery of better-quality software and an improved user experience. The virtual appliance is an emerging new development for the software industry.

IBM is turning to technology from Novell to build Linux OS powered software appliances -- a move that aims to deliver easy-to-deploy software for physical, virtual and cloud-based environments in use at small to midsized businesses.

Ubuntu developers recently began discussing plans for deploying virtual appliances via Debian packages, a move which would open up exciting opportunities, especially in the server market.  Here's the scope, with some thoughts.

TurnKey Linux, an Ubuntu based project, recently announced its largest release to date, which includes 25 new additions to its free virtual appliance library featuring some of the world's best open source software. Support has been added for Amazon EC2 cloud and the OVF virtual appliance format.

Virtualization giant VMware this week announced a new open source version of its virtual desktop software, dubbed VMware View Open Client. Licensed under the LGPL, the open source virtual desktop software and its source code will be available, primarily to VMware partners, to spur development of supporting virtual desktop software.

Not only has virtualization advanced the state of the art in maximizing server efficiency, it has also opened the door to new technologies that were not possible before. One of these technologies is the virtual appliance, which fundamentally changes the way software is delivered, configured, and managed.

Since earlier this year, commercial Linux distributor Novell has been working to get a set of online tools together, which it hopes will make it the force behind virtual machine server appliances. Today, the online tool, called SUSE Studio, and the related SUSE appliance program go into production.