Nuklear is graphical user interface toolkit written in ANSI C.
It’s a single header library written in C89 (ANSI C), with small codebase (~18kLOC)
It’s focussed on portability, efficiency and simplicity and have no dependencies.
Documentation is available at https://rawgit.com/vurtun/nuklear/master/doc/nuklear.html
and code at https://github.com/vurtun/nuklear
I wonder if some people have ever considered writing a Julia wrapper for Nuklear