The download site didn't have an rpm for this distribution (clone of RHEL 7) so I figured out how to install xpra on CentOS 7. The key is to rebuild Fedora 20 src.rpms. You'll need to do this for PyOpenGL, pygtkglext, gtkglext and xpra, as well as install python3, tkinter, mesa-libGLU-devel, etc. in the usual way. Seems to run OK. Bob T.