I get an error while install xbrightness.
How can I install it?
I doubt that was compiled on Fedora. Even on rawhide, libXaw only provides
Looking a little deeper, it looks like you're trying to install an openSUSE package on Fedora. While at times that might work, I wouldn't recommend it.
As a general rule, you might be able to rebuild source rpms from other distributions on Fedora, but there's no guarantees that the package names for the build dependencies will line up. In this case, they don't.
That said, it is pretty easy to figure out what the build dependencies should be. I've done just that. There is a totally untested package here: http://steve.fedorapeople.org/xbrightness/