If you have a Reader Protocol compliant reader in front of you or you want to communicate with a reader that is online via a GUI, get started with the Reader RP Client.
If you have a Reader Protocol compliant reader in front of you or you want to communicate with a reader that is online from within your Java application, get started with the Reader RP Proxy.
If you don't have access to a Reader Protocol compliant reader, get started with the Reader RP/RM Core.
If this does not make sense to you, have a look at the demos to get a better idea of the functionality the Fosstrak Reader project offers.