diff --git a/bin/gtk-mandelbrot.pl b/bin/gtk-mandelbrot.pl
new file mode 100755
index 0000000..7ef0456
--- /dev/null
+++ b/bin/gtk-mandelbrot.pl
@@ -0,0 +1,306 @@
+use v6;
+
+my $height = @*ARGS[0] // 1001;
+$height = +$height;
+my $width = $height;
+my $max_iterations = 50;
+
+my $upper-right = -2 + (5/4)i;
+my $upper-right-re = -2;
+my $upper-right-im = 5/4;
+my $lower-left = 1/2 - (5/4)i;
+my $lower-left-re = 1/2;
+my $lower-left-im = -5/4;
+
+my @color_map = (
+    "0 0 0",
+    "0 0 252",
+    "64 0 252",
+    "124 0 252",
+    "188 0 252",
+    "252 0 252",
+    "252 0 188",
+    "252 0 124",
+    "252 0 64",
+    "252 0 0",
+    "252 64 0",
+    "252 124 0",
+    "252 188 0",
+    "252 252 0",
+    "188 252 0",
+    "124 252 0",
+    "64 252 0",
+    "0 252 0",
+    "0 252 64",
+    "0 252 124",
+    "0 252 188",
+    "0 252 252",
+    "0 188 252",
+    "0 124 252",
+    "0 64 252",
+    "124 124 252",
+    "156 124 252",
+    "188 124 252",
+    "220 124 252",
+    "252 124 252",
+    "252 124 220",
+    "252 124 188",
+    "252 124 156",
+    "252 124 124",
+    "252 156 124",
+    "252 188 124",
+    "252 220 124",
+    "252 252 124",
+    "220 252 124",
+    "188 252 124",
+    "156 252 124",
+    "124 252 124",
+    "124 252 156",
+    "124 252 188",
+    "124 252 220",
+    "124 252 252",
+    "124 220 252",
+    "124 188 252",
+    "124 156 252",
+    "180 180 252",
+    "196 180 252",
+    "216 180 252",
+    "232 180 252",
+    "252 180 252",
+    "252 180 232",
+    "252 180 216",
+    "252 180 196",
+    "252 180 180",
+    "252 196 180",
+    "252 216 180",
+    "252 232 180",
+    "252 252 180",
+    "232 252 180",
+    "216 252 180",
+    "196 252 180",
+    "180 252 180",
+    "180 252 196",
+    "180 252 216",
+    "180 252 232",
+    "180 252 252",
+    "180 232 252",
+    "180 216 252",
+    "180 196 252",
+    "0 0 112",
+    "28 0 112",
+    "56 0 112",
+    "84 0 112",
+    "112 0 112",
+    "112 0 84",
+    "112 0 56",
+    "112 0 28",
+    "112 0 0",
+    "112 28 0",
+    "112 56 0",
+    "112 84 0",
+    "112 112 0",
+    "84 112 0",
+    "56 112 0",
+    "28 112 0",
+    "0 112 0",
+    "0 112 28",
+    "0 112 56",
+    "0 112 84",
+    "0 112 112",
+    "0 84 112",
+    "0 56 112",
+    "0 28 112",
+    "56 56 112",
+    "68 56 112",
+    "84 56 112",
+    "96 56 112",
+    "112 56 112",
+    "112 56 96",
+    "112 56 84",
+    "112 56 68",
+    "112 56 56",
+    "112 68 56",
+    "112 84 56",
+    "112 96 56",
+    "112 112 56",
+    "96 112 56",
+    "84 112 56",
+    "68 112 56",
+    "56 112 56",
+    "56 112 68",
+    "56 112 84",
+    "56 112 96",
+    "56 112 112",
+    "56 96 112",
+    "56 84 112",
+    "56 68 112",
+    "80 80 112",
+    "88 80 112",
+    "96 80 112",
+    "104 80 112",
+    "112 80 112",
+    "112 80 104",
+    "112 80 96",
+    "112 80 88",
+    "112 80 80",
+    "112 88 80",
+    "112 96 80",
+    "112 104 80",
+    "112 112 80",
+    "104 112 80",
+    "96 112 80",
+    "88 112 80",
+    "80 112 80",
+    "80 112 88",
+    "80 112 96",
+    "80 112 104",
+    "80 112 112",
+    "80 104 112",
+    "80 96 112",
+    "80 88 112",
+    "0 0 64",
+    "16 0 64",
+    "32 0 64",
+    "48 0 64",
+    "64 0 64",
+    "64 0 48",
+    "64 0 32",
+    "64 0 16",
+    "64 0 0",
+    "64 16 0",
+    "64 32 0",
+    "64 48 0",
+    "64 64 0",
+    "48 64 0",
+    "32 64 0",
+    "16 64 0",
+    "0 64 0",
+    "0 64 16",
+    "0 64 32",
+    "0 64 48",
+    "0 64 64",
+    "0 48 64",
+    "0 32 64",
+    "0 16 64",
+    "32 32 64",
+    "40 32 64",
+    "48 32 64",
+    "56 32 64",
+    "64 32 64",
+    "64 32 56",
+    "64 32 48",
+    "64 32 40",
+    "64 32 32",
+    "64 40 32",
+    "64 48 32",
+    "64 56 32",
+    "64 64 32",
+    "56 64 32",
+    "48 64 32",
+    "40 64 32",
+    "32 64 32",
+    "32 64 40",
+    "32 64 48",
+    "32 64 56",
+    "32 64 64",
+    "32 56 64",
+    "32 48 64",
+    "32 40 64",
+    "44 44 64",
+    "48 44 64",
+    "52 44 64",
+    "60 44 64",
+    "64 44 64",
+    "64 44 60",
+    "64 44 52",
+    "64 44 48",
+    "64 44 44",
+    "64 48 44",
+    "64 52 44",
+    "64 60 44",
+    "64 64 44",
+    "60 64 44",
+    "52 64 44",
+    "48 64 44",
+    "44 64 44",
+    "44 64 48",
+    "44 64 52",
+    "44 64 60",
+    "44 64 64",
+    "44 60 64",
+    "44 52 64",
+    "44 48 64",
+);
+
+constant $GTK  = "gtk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f";
+constant $GDK  = "gdk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f";
+
+constant Application    = CLR::("Gtk.Application,$GTK");
+constant Window         = CLR::("Gtk.Window,$GTK");
+constant GdkCairoHelper = CLR::("Gdk.CairoHelper,$GDK");
+constant GdkGC          = CLR::("Gdk.GC,$GDK");
+constant GdkColor       = CLR::("Gdk.Color,$GDK");
+constant GtkDrawingArea = CLR::("Gtk.DrawingArea,$GTK");
+constant SystemByte     = CLR::("System.Byte");
+
+my @red =   @color_map.map({ SystemByte.Parse($_.comb(/\d+/)[0]) });
+my @green = @color_map.map({ SystemByte.Parse($_.comb(/\d+/)[1]) });
+my @blue =  @color_map.map({ SystemByte.Parse($_.comb(/\d+/)[2]) });
+
+Application.Init;
+my $window = Window.new("mandelbrot");
+my $windowSizeX = 321; my $windowSizeY = 321;
+$window.Resize($windowSizeX, $windowSizeY);  # TODO: resize at runtime NYI
+my $drawingarea = GtkDrawingArea.new;
+$drawingarea.add_ExposeEvent(&ExposeEvent);
+$window.add_DeleteEvent(&DeleteEvent);
+$window.Add($drawingarea);
+$window.ShowAll;
+Application.Run;  # end of main program, it's all over when this returns
+
+sub DeleteEvent($obj, $args) {  #OK not used
+    Application.Quit;
+};
+
+sub ExposeEvent($obj, $args)
+{
+    $args;  # suppress "declared but not used" "Potential difficulties"
+    
+    my $start-time = time;
+    my $windowX=0; my $windowY=0; my $windowWidth=0; my $windowHeight=0; my $windowDepth=0;
+    $obj.GdkWindow.GetGeometry($windowX, $windowY, $windowWidth, $windowHeight, $windowDepth);
+
+    sub WhichComplex($x, $y) {
+        my $delta-re = $upper-right-re - $lower-left-re;
+        my $delta-im = $upper-right-im - $lower-left-im;
+        $upper-right - ($x / $windowWidth) * $delta-re
+                     - ($y / $windowHeight) * $delta-im * i;
+    }
+
+    for 0 .. $windowHeight -> $y {
+        for 0 .. $windowWidth -> $x {
+            my $c = WhichComplex($x, $y);
+            my $value = mandel($c);
+            my $gc = GdkGC.new($obj.GdkWindow);
+            my $color = GdkColor.new(@red[$value], @green[$value], @blue[$value]);
+            $obj.GdkWindow.Colormap.AllocColor($color, False, True);
+            $gc.Foreground = $color;
+            $obj.GdkWindow.DrawPoint($gc, $x, $y);
+        }
+    }
+    
+    my $elapsed = time - $start-time;
+    say "$elapsed seconds";
+};
+
+sub mandel(Complex $c) {
+    my $z = 0i;
+    my $i;
+    loop ($i = 0; $i < $max_iterations; $i++) {
+        if ($z.abs > 2) {
+            return $i + 1;
+        }
+        $z = $z * $z + $c;
+    }
+    return 0;
+}