A computer system has one or more software contexts that share use of a memory that is divided into units such as pages. In the preferred embodiment of the invention, the contexts are, or include, virtual machines running on a common hardware platform. The contents, as opposed to merely the addresses...http://www.google.de/patents/US7620766?utm_source=gb-gplus-sharePatent US7620766 - Transparent sharing of memory pages using content comparison
