See Platform Dependencies in The Racket Drawing Toolkit for information on platform library dependencies for racket/draw. On Unix, GTK+ 3 is used if its libraries can be found and the PLT_GTK2 environment is not defined. Otherwise, GTK+ 2 is used. The following additional system libraries must be installed for racket/gui/base in either case:
"libgdk-3.0[.0]" (GTK+ 3) or "libgdk-x11-2.0[.0]" (GTK+ 2)
"libgdk_pixbuf-2.0[.0]" (GTK+ 2)
"libgtk-3.0[.0]" (GTK+ 3) or "libgtk-x11-2.0[.0]" (GTK+ 2)
"libgio-2.0[.0]" — optional, for detecting interface scaling
"libGL[.1]" — optional, for OpenGL support
"libunique-1.0[.0]" — optional, for single-instance support (GTK+ 2)