[Pugl](https://github.com/lv2/pugl) is a cross-platform event-driven GUI library that was originally designed for making audio plugins but claims that it is useful for games and other applications as well. It is written in C and includes binding for C++. In addition to the native windowing support for Windows, Mac, and X11 it also supports [[GUI - Cairo]], [[Vulkan]], and [[OpenGL]] backends on each of those targets.