But .. how would that work ? What does "language-abstracted" means for something which is specifically about a language ? E.g. moc in c++ looks for your classe

But .. how would that work ? What does "language-abstracted" means for something which is specifically about a language ? E.g. moc in c++ looks for your classes with a Q_OBJECT macro to generate the matching reflection & metaobject data in a .cpp: how does that work in a language that doesn't have preprocessor macros, or maybe even classes, e.g. Scheme or some BASIC dialect ? In addition, moc is only necessary for languages that do not have proper reflection & code generation facilities - if they do, it's entirely unnecessary as the metaobject code can just be generated in-language as part of the bindings you're mentioning. E.g. consider the python Qt bindings: they don't need a moc. Same for D.