Part Introductory : a Few Definitions and Two Examples.- Part II : I The Reliable Broadcast Communication Abstraction.- Reliable Broadcast in the Presence of Process Crash Failures.- Reliable Broadcast in the Presence of Process Crashes and Unreliable Channels.- Reliable Broadcast in the Presence of Byzantine Processes.- Part III : The Read/Write Register Communication Abstraction.- The Read/Write Register Abstraction.- Building Read/Write Registers Despite Asynchrony and Less Than Half of Processes Crash (t