I run Drago on Linux, using Wine. However, shadows under stones apparently is a major issue on that platform. MultiGo, e.g., deals correctly with shadows, but widgets have a pink background (in version 4, but not in version 3!) Many Faces of Go v12 has shadows, but color is reversed (white shadows), and the stones have a square mask that does not properly render a round appearance. Some sgf viewers intended for Windows have a more primitive, non-3D mode that renders stones as b&w circles, and those work fine. So maybe Gilles can do shadows, but should he, considering these odd behaviors under Wine. Maybe the fault is Wine's, but the victims of the fault will be running Drago on the only platform they have, so....?