This is part of The Pile, a partial archive of some open source mailing lists and newsgroups.
An odd hint from Tet of technocrat.net:
http://technocrat.net/960401352/index_html
Re: what is Plan 9? a quick overview.
by Tet on Tuesday June 13, @08:15AM
a person can run it's windowing system
(called 8 and a half) *inside* a window of
its windowing system (recursively). try
that with X!
Easy -- use Xnest. It gives you a complete X server
in an X window. I've used it quite a lot in the past
for testing out new window mangers.
See http://www.xfree86.org/4.0/Xnest.1.html.