diff --git a/share/dynamic-graph/scripts/shell.dg b/share/dynamic-graph/scripts/shell.dg
new file mode 100644
index 0000000000000000000000000000000000000000..35aed3c3f5a49388bc023310b80c5d060fa438c2
--- /dev/null
+++ b/share/dynamic-graph/scripts/shell.dg
@@ -0,0 +1,23 @@
+import shell-functions
+# DO NOT MOVE THIS LINE: comments are not implemented before.
+
+# Copyright 2010, Thomas Moulard, JRL, CNRS/AIST.
+# .
+# This file is part of dynamic-graph.
+# dynamic-graph is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public License
+# as published by the Free Software Foundation, either version 3 of
+# the License, or (at your option) any later version.
+# .
+# dynamic-graph is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Lesser Public License for more details.  You should have
+# received a copy of the GNU Lesser General Public License along with
+# dynamic-graph. If not, see <http://www.gnu.org/licenses/>.
+
+# This script provides basic shell tools.
+# This file should ALWAYS be imported as it provides core features
+# such as comments.
+
+import shell-procedure
diff --git a/share/dynamic-graph/scripts/tracer.dg b/share/dynamic-graph/scripts/tracer.dg
new file mode 100644
index 0000000000000000000000000000000000000000..f47d38734ad3913b80a395f988091904aefe004f
--- /dev/null
+++ b/share/dynamic-graph/scripts/tracer.dg
@@ -0,0 +1,23 @@
+import shell.dg
+# Copyright 2010, Thomas Moulard, JRL, CNRS/AIST.
+# .
+# This file is part of dynamic-graph.
+# dynamic-graph is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public License
+# as published by the Free Software Foundation, either version 3 of
+# the License, or (at your option) any later version.
+# .
+# dynamic-graph is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Lesser Public License for more details.  You should have
+# received a copy of the GNU Lesser General Public License along with
+# dynamic-graph. If not, see <http://www.gnu.org/licenses/>.
+
+# This script provides real-time logging facilities.
+# .
+# The tracer can be used to log signal values without
+# intefering with the real-time properties of dynamic-graph.
+
+import tracer-real-time
+import tracer