Deepfish was an experimental browsing software system for Windows Mobile devices that used a zooming user interface, being developed at Microsoft Live Labs.

Deepfish consisted of a light-weight browser client powered by a server backend which does most of the processing.

The server streams only the data that is visible at any moment, which improves load times and responsiveness.

Despite the increased speed in Deepfish, it's quite bandwidth heavy and can render pages slowly if it were launched on a device with lower specifications.

Deepfish was retired on 30 September 2008 while important features including JavaScript, AJAX, cookies, ActiveX controls and HTTP POST were not implemented.