diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..9ef5e84
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,12 @@
+[submodule "git-repos/hellogitworld"]
+	path = git-repos/hellogitworld
+	url = https://github.com/githubtraining/hellogitworld.git
+[submodule "git-repos/example-submodule"]
+	path = git-repos/example-submodule
+	url = https://github.com/githubtraining/example-submodule
+[submodule "git-repos/moreutils"]
+	path = git-repos/moreutils
+	url = git://git.kitenet.net/moreutils
+[submodule "git-repos/sed"]
+	path = git-repos/sed
+	url = http://git.savannah.gnu.org/r/sed.git
diff --git a/git-repos/Makefile b/git-repos/Makefile
new file mode 100644
index 0000000..4d29c33
--- /dev/null
+++ b/git-repos/Makefile
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+SUBMODULES = $(patsubst %/,%,$(dir $(wildcard */.git)))
+EXPORTS =  $(patsubst %,%.fast-export.xz,$(SUBMODULES))
+
+all: export
+export: $(EXPORTS)
+
+%.fast-export.xz: $(wildcard ../.git/modules/git-repos/%/refs/*/*)  # (re-)export if refs have changed
+	(cd $* && git fast-export --all --signed-tags=verbatim) | xz -c > $@
+
+distclean:
+	rm -f $(EXPORTS)
diff --git a/git-repos/example-submodule b/git-repos/example-submodule
new file mode 160000
index 0000000..9768d0b
--- /dev/null
+++ b/git-repos/example-submodule
@@ -0,0 +1 @@
+Subproject commit 9768d0b576dbaaecd80abedad6dfd0d72f1476da
diff --git a/git-repos/example-submodule.fast-export.xz b/git-repos/example-submodule.fast-export.xz
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index 0000000..3c2adc8
Binary files /dev/null and b/git-repos/example-submodule.fast-export.xz differ
diff --git a/git-repos/hellogitworld b/git-repos/hellogitworld
new file mode 160000
index 0000000..ef7bebf
--- /dev/null
+++ b/git-repos/hellogitworld
@@ -0,0 +1 @@
+Subproject commit ef7bebf8bdb1919d947afe46ab4b2fb4278039b3
diff --git a/git-repos/hellogitworld.fast-export.xz b/git-repos/hellogitworld.fast-export.xz
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index 0000000..1a6c7a9
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diff --git a/git-repos/moreutils b/git-repos/moreutils
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index 0000000..b921969
--- /dev/null
+++ b/git-repos/moreutils
@@ -0,0 +1 @@
+Subproject commit b92196912d363683f24e71b0b2351324d50f5375
diff --git a/git-repos/moreutils.fast-export.xz b/git-repos/moreutils.fast-export.xz
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index 0000000..416b417
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diff --git a/git-repos/sed b/git-repos/sed
new file mode 160000
index 0000000..31c84cb
--- /dev/null
+++ b/git-repos/sed
@@ -0,0 +1 @@
+Subproject commit 31c84cbcfd2516e278a2a75523c7d5ad78f7bc57
diff --git a/git-repos/sed.fast-export.xz b/git-repos/sed.fast-export.xz
new file mode 100644
index 0000000..44ceb82
Binary files /dev/null and b/git-repos/sed.fast-export.xz differ