This is another milestone in the development of the compiler - being able to compile COBOL programs that use GTK#. Again, I believe this may be the first time anyone's written a GTK# program in COBOL. The screenshot below shows the example from Mono's GTK Sharp beginners guide translated into COBOL and running on Mono on OS X.

The compiler can be downloaded from here. Some GTK# COBOL source code will be in the example section soon.