I wish someone would pick back up wxc, the C interface for wxWidgets. IIRC the latest updates are in the wxc folder of wxHaskell [1]. That any non-C++ language is able to somewhat "import C++" (i.e. Nim and D) is nice and all, but doesn't really help the larger community and can be brittle in some C++ situations.

1 - https://github.com/wxHaskell/wxHaskell