I can not tell you where the GUI frontend to RPM is; if it exists. I can tell you that you can run RPM (as root) in a terminal.
Let's say that you want to install foo. Examine your disks or whatever to find foo-1.1-1.ppc.rpm or something like that. Then you can type
rpm -i -v [path]/foo-1.1-1.ppc.rpm
And that should do it. No gcc? if you installed as a workstation, and not as a desktop (assuming you went with the defaults on the install) you should have it already. Try typing
which gcc
to see what you get. Hope this helped.
