diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..66545e9
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "grid"]
+	path = grid
+	url = https://git.ufp.institute/ufp/hdk-grid.git
+[submodule "sdl"]
+	path = sdl
+	url = https://git.ufp.institute/ufp/hdk-sdl.git
+[submodule "is3r"]
+	path = is3r
+	url = https://git.ufp.institute/ufp/hdk-is3r.git
diff --git a/grid b/grid
new file mode 160000
index 0000000..81ecc87
--- /dev/null
+++ b/grid
@@ -0,0 +1 @@
+Subproject commit 81ecc87d39a338617341b10ffef648f3b9dccf36
diff --git a/is3r b/is3r
new file mode 160000
index 0000000..e25a28f
--- /dev/null
+++ b/is3r
@@ -0,0 +1 @@
+Subproject commit e25a28f3bf3847b297b99ac656b62e3735cfa923
diff --git a/sdl b/sdl
new file mode 160000
index 0000000..15bb051
--- /dev/null
+++ b/sdl
@@ -0,0 +1 @@
+Subproject commit 15bb051619e1b887652962435532fca61cf9bc94