Ghostzilla was an open source web browser for Microsoft Windows based on the Gecko HTML renderer used by Mozilla. It runs the browser inside the window space of another application e.g. in Microsoft Outlook, where the page was then made to look like the content one would expect in an email, leaving any passers-by with the impression the person was reading e-mail. [1]
Ghostzilla's Logo.
From May 2004 until January 2005, the project was removed from the website, due to a copyright claim from Mozilla. It later returned with open source code, but with warnings about the potential for misuse. As of February 2007, the site has been suspended and is no longer available.