all these 3 are JSF components and frameworks  supporting AJAX

ADF Rich Faces belongs to Oracle and will going to be donated to Apache as Apache RCF.
it is very huge and complicated and works very good inside oracle ADF framework.

RichFaces started by Exadel was a Redhat Jboss project good integration with Ajax4JSF.
it works very well with Seam and other jboss frameworks.

ICEFaces is project from a company dedicated to this product.

each has its own benefits and it depends on your needs.