Wicket is one more component framework like Tapestry, JSF or ASP.NET. However, it's light and very simple. Well, ASP.NET is simpler :)

One example (displays textarea with submit button and messages list):

public GuestBook()
{
 add(new CommentForm("commentForm"));
 add(commentListView = new ListView("comments", commentList)
 {
     public void populateItem(final ListItem listItem)
     {
         final Comment comment = (Comment)listItem.getModelObject();
         listItem.add(new Label("date", comment.getDate()));
         listItem.add(new MultiLineLabel("text", comment.getText()));
     }
 });
}