A 32-bit Linux binary can be downloaded from the JD-GUI homepage. The tar.gz file just contains a single binary executable. I installed it as follows:
tar -xzvf jd-gui-0.3.3.linux.i686.tar.gz 
sudo mv jd-gui /usr/local/binsudo yum install libcanberra-gtk2.i686 PackageKit-gtk-module.i686 gtk2-engines.i686If you're using GNOME as your desktop environment, you may also want to associate .class files with JD-GUI. To do so, open File Browser and find a .class file. Right-click on the class file and select Properties. Select the Open With tab, click the Add button, select "Use a custom command", enter "/usr/local/bin/jd-gui", and finally click the Add button. Now when you double-click on a .class file from the File Browser, it will open that file using JD-GUI.
 
