1. One or more non-transitory computer-readable storage mediums storing one or more sequences of instructions for managing a plurality of virtual machines upon a hardware device, which when executed by one or more processors, causes: in response to a software component determining, in consultation with a policy, that a tab of a web browser, in which content is displayed that was retrieved by a first virtual machine executing on said hardware device, has not been selected by a user or active within a specified time period, programmatically changing an operational state of the first virtual machine executing on the hardware device from a first state to a non-executing state, wherein said first virtual machine does not display said web browser on said hardware device, wherein said first virtual machine is separate from a second virtual machine, executing on said hardware device, which is responsible for displaying said web browser on said hardware device; and displaying, within the tab of the web browser, an image to represent the first virtual machine, wherein the image is based upon the state of the first virtual machine immediately prior to the first virtual machine entering the non-executing state.