What is it?
	Effect is to nest the window system
	Done by simply naming another window as root
	Different from Xnest in that it doesn't create a completely new
		window heirarchy.
	No performance loss with no duplicate window system structures.
	Shares some global resources causing difficulty.
	Allows cut/paste between nested and non-nested applications.
	
what is it good for
	window manager debugging?  No, doesn't solve grab contention.  Xnest
	encapsulating sophisticated user environments
		HP Vue is groady
	lying about root window geometry
		Some applications try to work on small screens and just lose
	Offering different default color model
		Testing applications
		Supporting broken applications
	Providing "rooms" like functionality with stock window managers
	Running multiple window managers at the same time where needed

history
	First attempted as xlib hack
	Couldn't work because of exposure of root window in protocol
	Shelved
	Became uninteresting as virtual window managers became popular?
	Revived here to solve some real problems wrt mixed window system 
	environments

problems
	exposure of real root window in protocol
		requests
		events
	global resource contention
		colormap
		input focus
		device grabs

architecture
	extension registers new pseudo-root window
	extension attaches display number to pseudo-root per screen
	clients connecting to display number see pseudo-root
	dynamic assignment of display numbers to pseudo-roots; can
		use core display number
	redirection of requests manipulating some contended global resources
	requires cooperation of pseudo-root manager for complete
		implementation

problems which were solved
	event/request spoofing
	input focus management
	colormap management

problems which weren't solved
	server grabs
	device grabs

conclusions
