So you’ve installed Fedora Core 6, and the RealPlayer RPM from here. You go to Applications → Sound & Video → RealPlayer 10, and… nothing happens.
Open up a terminal. Try to run RealPlayer from there. Chances are you’ll see this:
[rich@penguin ~]$ realplay
/usr/local/RealPlayer/realplay.bin: error while loading shared libraries: libstdc++.so.5: cannot open shared object file: No such file or directory
This is really easy to fix. Just type
yum install compat-libstdc++-33
and RealPlayer will work, from the terminal or from the Applications menu.