Software appliances

operating system distribution/image/copy bootable from CD, DVD and possibly other similar media

computer data storage server

Openfiler is an operating system that provides file-based network-attached storage and block-based storage area network. It was created by Xinit Systems, and is based on the CentOS Linux distribution. It is free software licensed under the GNU GPLv2

virtual appliance within the Amazon EC2

pre-configured virtual machine image, ready to run on a hypervisor

open source project that provides pre-packaged server software appliances