On this page:
gui-available?
gui-dynamic-require

11 Dynamic Loading

 (require racket/gui/dynamic) package: base
The racket/gui/dynamic library provides functions for dynamically accessing the racket/gui/base library, instead of directly requiring racket/gui or racket/gui/base.

procedure

(gui-available?)  boolean?

Returns #t if dynamic access to the GUI bindings is available. The bindings are available if racket/gui/base has been loaded, instantiated, and attached to the namespace in which racket/gui/dynamic was instantiated.

procedure

(gui-dynamic-require sym)  any

  sym : symbol?
Like dynamic-require, but specifically to access exports of racket/gui/base.