Yes, this does look like an appjet clone. Not to take anything away from this implementation, however, because it looks like the author didnt know of appjet.

Appjet had the same concept: server side js based on rhino, persistent js object store, etc.The concept, however, was a little bit rudimentary: one app consisted of one js "file". You had to write every possible interaction as functions within that file. It did have an interesting function call based templating mechanism, however, something like so:

  print(DIV(
    FORM({action:"/", method:"get"},
      SPAN({style: "float: left;"}, "Show"),
        INPUT( {name: "count", value: count, size: "2", className: "in_box"} ),
      SPAN({style: "float: left;"}, "items"),
        INPUT( {value: "Go", className: "in_box", size: "1", type: "submit"} ),
      DIV({style: "clear: both;"})
    )
  ));

Appjet the company had made the source available for download a while ago, and it seems like these folks have run with it:http://apps.jgate.de/