diff --git a/GNUmakefile b/GNUmakefile
new file mode 100644
index 00000000..ef82c2d3
--- /dev/null
+++ b/GNUmakefile
@@ -0,0 +1,5 @@
+.PHONY: minify
+
+minify:
+	make -C img/ minify
+	make -C  js/ minify
diff --git a/img/GNUmakefile b/img/GNUmakefile
new file mode 100644
index 00000000..09b13069
--- /dev/null
+++ b/img/GNUmakefile
@@ -0,0 +1,8 @@
+OPTIPNG ?= optipng
+
+.PHONY: minify
+minify: $(patsubst %.png,%.png.opt,$(wildcard *.png))
+
+%.png.opt: %.png
+	${OPTIPNG} $<
+	@touch $@
diff --git a/js/GNUmakefile b/js/GNUmakefile
new file mode 100644
index 00000000..6cdccc1e
--- /dev/null
+++ b/js/GNUmakefile
@@ -0,0 +1,9 @@
+CLOSUREJAR ?= ../compiler.jar
+
+.PHONY: minify
+minify: $(patsubst %.js,%.js.old,$(wildcard *.js))
+
+%.js.old: %.js
+	@mv -f $< $@
+	java -jar ${CLOSUREJAR} --compilation_level SIMPLE_OPTIMIZATIONS $@ > $<
+	@touch $@