diff --git a/demo/.gitignore b/demo/.gitignore
new file mode 100644
index 0000000..ca81873
--- /dev/null
+++ b/demo/.gitignore
@@ -0,0 +1,2 @@
+dwarf-synthesis
+tests/data*
diff --git a/demo/Makefile b/demo/Makefile
new file mode 100644
index 0000000..db40a01
--- /dev/null
+++ b/demo/Makefile
@@ -0,0 +1,9 @@
+all:
+	@>&2 echo "Please provide an explicit target"
+	@exit 1
+
+tests/data:
+	dd if=/dev/urandom of="$@" bs=512K count=4
+
+clean:
+	rm -f tests/data.gz tests/gzip.synth
diff --git a/demo/tests/gzip b/demo/tests/gzip
new file mode 100755
index 0000000..ee28dc2
Binary files /dev/null and b/demo/tests/gzip differ