Glade built for RHEL4 is no longer actively supported. I have an old build for this that works if you need it; however Qt stopped building on RHEL4 on version 4.8.0 so newer versions of the code cannot run on this old OS.
For RHEL5, same thing has happened with the move to Qt 5.x, as the Qt folks no longer support this OS. I can maintain a branch of the code that will run on Qt 4.8.x for a while but don't want to do this indefinitely.
RHEL6 is stable and supported as it Ubuntu 10.04. Ubuntu 12.04 is now supported and any feedback on problems with this build would be appreciated.