New features in version 5
The components
Exported PHP classes are now called components, and they can be of three different types. Some components can be attached to DOM nodes, whose content they will manage.
The call factories
The call factories in PHP have been enriched, and now support calls to Javascript functions and event handlers, as well as their parameters.
The commands in responses
The command names and formats in responses are now more meaningful, and their processing in Javascript is improved. Deprecated commands have also been removed.
The dialog libraries
The dialog libraries now contain only Javascript code, in a single and tiny object. They will therefore be much easier to create and maintain.