Atoms can contain any character if they are enclosed within single quotes and an escape convention exists which allows any character to be used within an atom. It is also a garbage-collected runtime system. Messages can be sent to and received from ports, but these messages must obey the so-called "port protocol." Ports are used to communicate with the external world. The syntax {D1,D2,...,Dn} denotes a tuple whose arguments are D1, D2, ... Dn.
