Google Web Toolkit - Remote Procedure Calls
RequestFactory is a component of the Google Web Toolkit that targets developers building data-oriented (CRUD) applications.
"Go with gwt-rpc or better newer with requestfactory"
from question "Best architecture for applications in GWT"
"My understanding is the requestfactory is more efficient and recommended over gwt-rpc but it s more of a data entity persistence framework than a request-response framework like rpc"
from question "GWT-RPC or RequestFactory for Authentication?"