Persistence Dapplets can have persistent state. For instance, a dapplet may manage your calendar. We think of the files that form the persistent state as private data members of the dapplet. Methods A collection of dapplets can be interconnected to form a distributed network. The methodology for creating and reasoning about dapplet networks is similar to that employed for creating and reasoning about structures of objects.
Any object can call a public method of another object.
We do not, however, want any dapplet to execute methods in another dapplet for several reasons. A dapplet has a collection of interfaces called inboxes. Invocation of a method is requested by sending a message to an inbox. For instance, calendar manager dapplets of members of my group can have access to an interface that is not accessible by the general public. A dapplet can deny a request for a method invocation or accept it.