Each Action class defines an abstraction, but the abstraction is determined by the HTTP procotol request mechanism rather than by an object-oriented analysis
Wicket is fully object-oriented. You work with hierarchies of components and design your application as such.
Wicket markup files are as close to pure HTML as it is possible to get. Where Wicket does introduce content into the markup it is very clean and complies with all XHTML standards
Wicket is based around intercepting each HTTP request to a web application and directing it to a specific Action class that handles the request