Does copy and paste work between xephyr and the originating Xorg?
Adding Linux Support: It makes a lot of sense to extend the program to support Linux for pure Linux users. To do so will require supporting at least GNOME and KDE, the most popular Linux windows managers. You can access Gnome's clipboard using pygtk and KDE's clipboard using pyqt. Another option is to require that the target machines have xsel or xclip, which work very much like pbcopy/pbpaste and implement Linux clipboard support on top of those.