(link to Michael Floyd's presentation: )
See slides provided by prof Rosenschein for Wooldridge's book chapter on the topic 
motivation: for agents to cooperate, coordinate, negotiate or compete in an open system environment, they need first to be able to communicate.
To make such communication possible, agents usually rely on a SharedOntology and a semi-standard communication language, based on the theory of SpeechActs.
Some known ACLs: