1. A method comprising: receiving, at a network interface device, specification input from a user for an intended use and deployment of a portion of an existing computing application in a virtual machine computing environment, to add-on to or enhance functionality of the existing computing application, wherein the input from the user identifies the virtual machine computing environment; selecting, by the network interface device, a virtual appliance template for the portion of the existing computing application based on the received specification input from the user, the virtual appliance template including binaries, configuration files, and data files of the portion of the existing computing application; transporting, by the network interface device, the virtual appliance template for the portion of the existing computing application and a script to an agent, of the virtual machine computing environment that was identified based on input from the user; wherein the script is executed by the agent to instantiate the virtual appliance template for the portion of the existing computing application within the virtual machine computing environment; and transmitting, by the network interface device, a message to a recipient indicating the virtual appliance template for the portion of the existing computing application has been instantiated and is available for use.