True, but it is not like dojo is continue to do that. Dojo is going to a 2.0 release and there is a massive change between 1.0 and 2.0, primarily AMD. Dojo has previously shown a long history of backward compatibility. One of concerns of many dojo developers is that they should abandon the old code and directly switch to new one as the transition period is not doing any good to new developers trying to learn dojo, but if you have already written an app, dojo provides excellent backward compatibility.