I'll try to explain it but first of all, there is a newer version, 4.5.5 and 4.5.6 will be released soon
The three jars that you listed come from richfaces distribution zip and all three are necessary. You need to include these three jars if you have Ant-based project.
If you use Maven for dependency management, you only need to include one dependency org.richfaces:richfaces:4.5.5.Final and all other dependencies will be downloaded automatically. Your project will end up with three jars included... org.richfaces:richfaces, org.richfaces:richfaces-a4j and org.richfaces:richfaces-core. These are exactly the same bits but richfaces.jar is renamed to richfaces-rich.jar in distribution zip.
Thank you Pavol! The jars are downloaded as you have mentioned.
As per your comments, I am able to download three jars -
I am getting into a weird situation which I took a lot of time to figure it out.
Since richfaces and a4j jars both have similar folder structure (org.richfaces.component), I am not able to import org.richfaces.component.UIDataAdaptor as it is being looked into org.richfaces.component in richfaces jar instead of richfaces-a4j jar. Because of this I am seeing warning in console "SEVERE: Class : org.richfaces.event.DataTablePreRenderListener not found.". When I tried to copy the same class (DataTablePreRenderListener) in my local folder structure, I could see that I am not able to import UIDataTable class. This ultimately is giving me an error "java.lang.NoClassDefFoundError: org/ajax4jsf/component/IterationStateHolder".
Can you please help me in understanding what am I missing here.