Hello Bad news: it seems that lablqt is in decadance. I'm still planning to implement inheritance (described here), but there are some problems with proof-of-concept app. It shows a widget and after pressing any key it crashes while calling caml_send0 function (autogenerated function for calling methods of ocaml objects. see ocaml sources) I will be glad if you will discuss this way of implementing inheritance, or give me a tip about crash. Best wishes, Kakadu