gtk-3-examples 3.24.36-1ubuntu1 (i386 binary) in ubuntu lunar

 GTK is a multi-platform toolkit for creating graphical user
 interfaces. Offering a complete set of widgets, GTK is suitable
 for projects ranging from small one-off tools to complete application
 suites.
 .
 This package contains the example files and a demonstration program
 for GTK3. It also contains the installed tests.