This package contains Xnest, a nested X server.
Xnest  is a client and a server.  Xnest is a client of the
real server which manages windows and graphics requests on
its  behalf.  Xnest is a server to its own clients.  Xnest
manages windows and graphics requests on their behalf.  To
these clients Xnest appears to be a conventional server.

WWW: http://www.xfree86.org/
