In the four chapters of Section 2, Toolkits Using Existing Widgets, we explored various graphical toolkits that provide a Go application different ways to work with existing widget sets. These toolkits provide Go APIs for either native widgets (such as CommonControls in Windows or the Cocoa widgets in macOS) or existing cross-platform toolkits (GTK+ and Qt). These widget sets are tried and tested, often supported by commercial companies, and have established developer tools to support their features (though not all functionality is available to the Go bindings). Applications built using these GUI APIs will vary in look according to the platform they are running on. This may, or may not, be desirable behavior.
In Section 3, Modern Graphical Toolkits, will look at graphical toolkits designed specifically for the Go language. As...