Whilst trolling around the file system of my cnmBook i came across this program
gtk-demo in /bin.
This is a demo program showing how to use the gtk libraries for creating windows and buttons etc for your own programs. There are code stubs available that can be copied into the Nedit program for incorporating into your program code.
use Xterm to launch it by typing gtk-demo from the $ prompt.
You will need the gcc compiler installed to compile your programs but this is covere elsewhere in this forum.
Regards
Paul