diff --git a/GNUmakefile b/GNUmakefile
new file mode 100644
index 00000000..71dc157c
--- /dev/null
+++ b/GNUmakefile
@@ -0,0 +1,6 @@
+vendor_list := mkernel miou zarith
+
+vendors:
+	@for v in $(vendor_list); do \
+	  [ ! -d "vendors/$v" ] && opam source $v --dir vendors/$v
+	done
diff --git a/source.sh b/source.sh
new file mode 100644
index 00000000..a9bf588e
--- /dev/null
+++ b/source.sh
@@ -0,0 +1 @@
+#!/bin/bash