diff --git a/frappy_psi/ACM1219.py b/frappy_psi/ACM1219.py
index c5c7223..4a49129 100644
--- a/frappy_psi/ACM1219.py
+++ b/frappy_psi/ACM1219.py
@@ -1,3 +1,22 @@
+# *****************************************************************************
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program 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 Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Paul M. Neves <pmneves@mit.edu>
+# *****************************************************************************
+
 from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Property, IntRange,\
     IDLE, BUSY, WARN, ERROR, Drivable, BoolType, Attached, StructOf
 
diff --git a/frappy_psi/RP100.py b/frappy_psi/RP100.py
index db63e6f..87e5974 100644
--- a/frappy_psi/RP100.py
+++ b/frappy_psi/RP100.py
@@ -1,3 +1,22 @@
+# *****************************************************************************
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program 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 Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Paul M. Neves <pmneves@mit.edu>
+# *****************************************************************************
+
 from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Property, IntRange,\
     IDLE, BUSY, WARN, ERROR, Drivable, BoolType, Attached
 from ast import literal_eval
diff --git a/frappy_psi/dummy.py b/frappy_psi/dummy.py
index 4b1c9e1..7fa888e 100644
--- a/frappy_psi/dummy.py
+++ b/frappy_psi/dummy.py
@@ -1,3 +1,22 @@
+# *****************************************************************************
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program 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 Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Paul M. Neves <pmneves@mit.edu>
+# *****************************************************************************
+
 from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Property, IntRange,\
     IDLE, BUSY, WARN, ERROR, Drivable, BoolType, Attached, Writable