Switch to Apache 2.0 license

To make the further integration into IaaS OSS (OpenStack and
CloudStack) easier, we switch to Apache 2.0 license.

ryu/app/wsapi.py is still under GPL3 or later. We replace it later.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

37 files changed, 551 insertions, 990 deletions

diff --git a/COPYING b/COPYING
deleted file mode 100644
index 94a9ed02..00000000
--- a/COPYING
+++ /dev/null
@@ -1,674 +0,0 @@
-                    GNU GENERAL PUBLIC LICENSE
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-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
-IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  16. Limitation of Liability.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
-THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
-GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
-USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
-DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
-PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
-EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGES.
-
-  17. Interpretation of Sections 15 and 16.
-
-  If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
-
-                     END OF TERMS AND CONDITIONS
-
-            How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-state the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) <year>  <name of author>
-
-    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 3 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, see <http://www.gnu.org/licenses/>.
-
-Also add information on how to contact you by electronic and paper mail.
-
-  If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
-
-    <program>  Copyright (C) <year>  <name of author>
-    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, your program's commands
-might be different; for a GUI interface, you would use an "about box".
-
-  You should also get your employer (if you work as a programmer) or school,
-if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
-
-  The GNU General Public License does not permit incorporating your program
-into proprietary programs.  If your program is a subroutine library, you
-may consider it more useful to permit linking proprietary applications with
-the library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/LICENSE b/LICENSE
index e96a659d..75b52484 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1 +1,202 @@
-GPL v3 only
+

+                                 Apache License

+                           Version 2.0, January 2004

+                        http://www.apache.org/licenses/

+

+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

+

+   1. Definitions.

+

+      "License" shall mean the terms and conditions for use, reproduction,

+      and distribution as defined by Sections 1 through 9 of this document.

+

+      "Licensor" shall mean the copyright owner or entity authorized by

+      the copyright owner that is granting the License.

+

+      "Legal Entity" shall mean the union of the acting entity and all

+      other entities that control, are controlled by, or are under common

+      control with that entity. For the purposes of this definition,

+      "control" means (i) the power, direct or indirect, to cause the

+      direction or management of such entity, whether by contract or

+      otherwise, or (ii) ownership of fifty percent (50%) or more of the

+      outstanding shares, or (iii) beneficial ownership of such entity.

+

+      "You" (or "Your") shall mean an individual or Legal Entity

+      exercising permissions granted by this License.

+

+      "Source" form shall mean the preferred form for making modifications,

+      including but not limited to software source code, documentation

+      source, and configuration files.

+

+      "Object" form shall mean any form resulting from mechanical

+      transformation or translation of a Source form, including but

+      not limited to compiled object code, generated documentation,

+      and conversions to other media types.

+

+      "Work" shall mean the work of authorship, whether in Source or

+      Object form, made available under the License, as indicated by a

+      copyright notice that is included in or attached to the work

+      (an example is provided in the Appendix below).

+

+      "Derivative Works" shall mean any work, whether in Source or Object

+      form, that is based on (or derived from) the Work and for which the

+      editorial revisions, annotations, elaborations, or other modifications

+      represent, as a whole, an original work of authorship. For the purposes

+      of this License, Derivative Works shall not include works that remain

+      separable from, or merely link (or bind by name) to the interfaces of,

+      the Work and Derivative Works thereof.

+

+      "Contribution" shall mean any work of authorship, including

+      the original version of the Work and any modifications or additions

+      to that Work or Derivative Works thereof, that is intentionally

+      submitted to Licensor for inclusion in the Work by the copyright owner

+      or by an individual or Legal Entity authorized to submit on behalf of

+      the copyright owner. For the purposes of this definition, "submitted"

+      means any form of electronic, verbal, or written communication sent

+      to the Licensor or its representatives, including but not limited to

+      communication on electronic mailing lists, source code control systems,

+      and issue tracking systems that are managed by, or on behalf of, the

+      Licensor for the purpose of discussing and improving the Work, but

+      excluding communication that is conspicuously marked or otherwise

+      designated in writing by the copyright owner as "Not a Contribution."

+

+      "Contributor" shall mean Licensor and any individual or Legal Entity

+      on behalf of whom a Contribution has been received by Licensor and

+      subsequently incorporated within the Work.

+

+   2. Grant of Copyright License. Subject to the terms and conditions of

+      this License, each Contributor hereby grants to You a perpetual,

+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

+      copyright license to reproduce, prepare Derivative Works of,

+      publicly display, publicly perform, sublicense, and distribute the

+      Work and such Derivative Works in Source or Object form.

+

+   3. Grant of Patent License. Subject to the terms and conditions of

+      this License, each Contributor hereby grants to You a perpetual,

+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

+      (except as stated in this section) patent license to make, have made,

+      use, offer to sell, sell, import, and otherwise transfer the Work,

+      where such license applies only to those patent claims licensable

+      by such Contributor that are necessarily infringed by their

+      Contribution(s) alone or by combination of their Contribution(s)

+      with the Work to which such Contribution(s) was submitted. If You

+      institute patent litigation against any entity (including a

+      cross-claim or counterclaim in a lawsuit) alleging that the Work

+      or a Contribution incorporated within the Work constitutes direct

+      or contributory patent infringement, then any patent licenses

+      granted to You under this License for that Work shall terminate

+      as of the date such litigation is filed.

+

+   4. Redistribution. You may reproduce and distribute copies of the

+      Work or Derivative Works thereof in any medium, with or without

+      modifications, and in Source or Object form, provided that You

+      meet the following conditions:

+

+      (a) You must give any other recipients of the Work or

+          Derivative Works a copy of this License; and

+

+      (b) You must cause any modified files to carry prominent notices

+          stating that You changed the files; and

+

+      (c) You must retain, in the Source form of any Derivative Works

+          that You distribute, all copyright, patent, trademark, and

+          attribution notices from the Source form of the Work,

+          excluding those notices that do not pertain to any part of

+          the Derivative Works; and

+

+      (d) If the Work includes a "NOTICE" text file as part of its

+          distribution, then any Derivative Works that You distribute must

+          include a readable copy of the attribution notices contained

+          within such NOTICE file, excluding those notices that do not

+          pertain to any part of the Derivative Works, in at least one

+          of the following places: within a NOTICE text file distributed

+          as part of the Derivative Works; within the Source form or

+          documentation, if provided along with the Derivative Works; or,

+          within a display generated by the Derivative Works, if and

+          wherever such third-party notices normally appear. The contents

+          of the NOTICE file are for informational purposes only and

+          do not modify the License. You may add Your own attribution

+          notices within Derivative Works that You distribute, alongside

+          or as an addendum to the NOTICE text from the Work, provided

+          that such additional attribution notices cannot be construed

+          as modifying the License.

+

+      You may add Your own copyright statement to Your modifications and

+      may provide additional or different license terms and conditions

+      for use, reproduction, or distribution of Your modifications, or

+      for any such Derivative Works as a whole, provided Your use,

+      reproduction, and distribution of the Work otherwise complies with

+      the conditions stated in this License.

+

+   5. Submission of Contributions. Unless You explicitly state otherwise,

+      any Contribution intentionally submitted for inclusion in the Work

+      by You to the Licensor shall be under the terms and conditions of

+      this License, without any additional terms or conditions.

+      Notwithstanding the above, nothing herein shall supersede or modify

+      the terms of any separate license agreement you may have executed

+      with Licensor regarding such Contributions.

+

+   6. Trademarks. This License does not grant permission to use the trade

+      names, trademarks, service marks, or product names of the Licensor,

+      except as required for reasonable and customary use in describing the

+      origin of the Work and reproducing the content of the NOTICE file.

+

+   7. Disclaimer of Warranty. Unless required by applicable law or

+      agreed to in writing, Licensor provides the Work (and each

+      Contributor provides its Contributions) on an "AS IS" BASIS,

+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or

+      implied, including, without limitation, any warranties or conditions

+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A

+      PARTICULAR PURPOSE. You are solely responsible for determining the

+      appropriateness of using or redistributing the Work and assume any

+      risks associated with Your exercise of permissions under this License.

+

+   8. Limitation of Liability. In no event and under no legal theory,

+      whether in tort (including negligence), contract, or otherwise,

+      unless required by applicable law (such as deliberate and grossly

+      negligent acts) or agreed to in writing, shall any Contributor be

+      liable to You for damages, including any direct, indirect, special,

+      incidental, or consequential damages of any character arising as a

+      result of this License or out of the use or inability to use the

+      Work (including but not limited to damages for loss of goodwill,

+      work stoppage, computer failure or malfunction, or any and all

+      other commercial damages or losses), even if such Contributor

+      has been advised of the possibility of such damages.

+

+   9. Accepting Warranty or Additional Liability. While redistributing

+      the Work or Derivative Works thereof, You may choose to offer,

+      and charge a fee for, acceptance of support, warranty, indemnity,

+      or other liability obligations and/or rights consistent with this

+      License. However, in accepting such obligations, You may act only

+      on Your own behalf and on Your sole responsibility, not on behalf

+      of any other Contributor, and only if You agree to indemnify,

+      defend, and hold each Contributor harmless for any liability

+      incurred by, or claims asserted against, such Contributor by reason

+      of your accepting any such warranty or additional liability.

+

+   END OF TERMS AND CONDITIONS

+

+   APPENDIX: How to apply the Apache License to your work.

+

+      To apply the Apache License to your work, attach the following

+      boilerplate notice, with the fields enclosed by brackets "[]"

+      replaced with your own identifying information. (Don't include

+      the brackets!)  The text should be enclosed in the appropriate

+      comment syntax for the file format. We also recommend that a

+      file or class name and description of purpose be included on the

+      same "printed page" as the copyright notice for easier

+      identification within third-party archives.

+

+   Copyright [yyyy] [name of copyright owner]

+

+   Licensed under the Apache License, Version 2.0 (the "License");

+   you may not use this file except in compliance with the License.

+   You may obtain a copy of the License at

+

+       http://www.apache.org/licenses/LICENSE-2.0

+

+   Unless required by applicable law or agreed to in writing, software

+   distributed under the License is distributed on an "AS IS" BASIS,

+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+   See the License for the specific language governing permissions and

+   limitations under the License.

diff --git a/bin/ryu-client b/bin/ryu-client
index e91ed739..9d5c7e4b 100755
--- a/bin/ryu-client
+++ b/bin/ryu-client
@@ -3,17 +3,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import sys
 from optparse import OptionParser
diff --git a/bin/ryu-manager b/bin/ryu-manager
index ef8355b1..f9bc562e 100755
--- a/bin/ryu-manager
+++ b/bin/ryu-manager
@@ -3,17 +3,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import gevent
 import gflags
diff --git a/ryu/app/cbench.py b/ryu/app/cbench.py
index 5dc64a94..4d89f867 100644
--- a/ryu/app/cbench.py
+++ b/ryu/app/cbench.py
@@ -1,5 +1,19 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 
 from ryu.controller import ofp_event
 from ryu.controller.handler import MAIN_DISPATCHER
diff --git a/ryu/app/client.py b/ryu/app/client.py
index c2c02a4a..c4728893 100644
--- a/ryu/app/client.py
+++ b/ryu/app/client.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011,2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import httplib
 import urlparse
diff --git a/ryu/app/event_dumper.py b/ryu/app/event_dumper.py
index ca6b5fd5..647f8da9 100644
--- a/ryu/app/event_dumper.py
+++ b/ryu/app/event_dumper.py
@@ -1,17 +1,19 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 
 import gflags
 import logging
diff --git a/ryu/app/rest.py b/ryu/app/rest.py
index 31164242..285cdbf0 100644
--- a/ryu/app/rest.py
+++ b/ryu/app/rest.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import json
 from ryu.exception import NetworkNotFound, NetworkAlreadyExist
diff --git a/ryu/app/rest_nw_id.py b/ryu/app/rest_nw_id.py
index 5422c81d..cb691032 100644
--- a/ryu/app/rest_nw_id.py
+++ b/ryu/app/rest_nw_id.py
@@ -1,17 +1,19 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 
 NW_ID_EXTERNAL = '__NW_ID_EXTERNAL__'
 NW_ID_UNKNOWN = '__NW_ID_UNKNOWN__'
diff --git a/ryu/app/simple_isolation.py b/ryu/app/simple_isolation.py
index 667739c7..8f2af492 100644
--- a/ryu/app/simple_isolation.py
+++ b/ryu/app/simple_isolation.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 import struct
diff --git a/ryu/app/simple_switch.py b/ryu/app/simple_switch.py
index 0d3436e0..a14bdb4f 100644
--- a/ryu/app/simple_switch.py
+++ b/ryu/app/simple_switch.py
@@ -1,16 +1,17 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 import struct
diff --git a/ryu/base/app_manager.py b/ryu/base/app_manager.py
index 39474e0e..4aae2903 100644
--- a/ryu/base/app_manager.py
+++ b/ryu/base/app_manager.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import itertools
 import logging
diff --git a/ryu/controller/__init__.py b/ryu/controller/__init__.py
index 059122a7..e69de29b 100644
--- a/ryu/controller/__init__.py
+++ b/ryu/controller/__init__.py
@@ -1,14 +0,0 @@
-# Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
-# Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
-#
-# 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, version 3 of the License.
-#
-# 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, see <http://www.gnu.org/licenses/>.
diff --git a/ryu/controller/controller.py b/ryu/controller/controller.py
index 100313e6..ad6127d2 100644
--- a/ryu/controller/controller.py
+++ b/ryu/controller/controller.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011, 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import contextlib
 import gflags
diff --git a/ryu/controller/dispatcher.py b/ryu/controller/dispatcher.py
index 35afb9fe..47248285 100644
--- a/ryu/controller/dispatcher.py
+++ b/ryu/controller/dispatcher.py
@@ -1,17 +1,19 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import copy
 import logging
 
diff --git a/ryu/controller/dp_type.py b/ryu/controller/dp_type.py
index 772f0481..dc9704c0 100644
--- a/ryu/controller/dp_type.py
+++ b/ryu/controller/dp_type.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 #
 # datapath type
diff --git a/ryu/controller/dpset.py b/ryu/controller/dpset.py
index fe42b95a..e5ef8198 100644
--- a/ryu/controller/dpset.py
+++ b/ryu/controller/dpset.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 
diff --git a/ryu/controller/event.py b/ryu/controller/event.py
index e831c076..539bc67f 100644
--- a/ryu/controller/event.py
+++ b/ryu/controller/event.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 class EventBase(object):
     # Nothing yet
diff --git a/ryu/controller/handler.py b/ryu/controller/handler.py
index 24944dc9..eaf235dd 100644
--- a/ryu/controller/handler.py
+++ b/ryu/controller/handler.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011, 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import copy
 import inspect
diff --git a/ryu/controller/mac_to_network.py b/ryu/controller/mac_to_network.py
index bc189296..e5f5a921 100644
--- a/ryu/controller/mac_to_network.py
+++ b/ryu/controller/mac_to_network.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 
diff --git a/ryu/controller/mac_to_port.py b/ryu/controller/mac_to_port.py
index f1db80f7..4d05a36d 100644
--- a/ryu/controller/mac_to_port.py
+++ b/ryu/controller/mac_to_port.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 from ryu.lib.mac import haddr_to_str
diff --git a/ryu/controller/network.py b/ryu/controller/network.py
index 0c61ba07..78f775bc 100644
--- a/ryu/controller/network.py
+++ b/ryu/controller/network.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 
diff --git a/ryu/controller/ofp_event.py b/ryu/controller/ofp_event.py
index a0b3a14b..41d0b406 100644
--- a/ryu/controller/ofp_event.py
+++ b/ryu/controller/ofp_event.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import inspect
 
diff --git a/ryu/exception.py b/ryu/exception.py
index f226960f..0a1e72ce 100644
--- a/ryu/exception.py
+++ b/ryu/exception.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 
 class RyuException(Exception):
diff --git a/ryu/flags.py b/ryu/flags.py
index c3ad4062..e9696208 100644
--- a/ryu/flags.py
+++ b/ryu/flags.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 """
 global flags
 """
diff --git a/ryu/lib/mac.py b/ryu/lib/mac.py
index 8a7009cd..4b548d54 100644
--- a/ryu/lib/mac.py
+++ b/ryu/lib/mac.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 DONTCARE = '\x00' * 6
 BROADCAST = '\xff' * 6
diff --git a/ryu/lib/track_instances.py b/ryu/lib/track_instances.py
index 62d8a128..1761d58a 100644
--- a/ryu/lib/track_instances.py
+++ b/ryu/lib/track_instances.py
@@ -1,16 +1,17 @@
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 # This is mixin class to track instances of a given class
 #
@@ -21,7 +22,6 @@
 # track of all instances by keeping a list of weak references to each
 # instance.
 
-
 from collections import defaultdict
 
 # Although WeakSet can be used directory, WeakValueDictionary is used instead
diff --git a/ryu/log.py b/ryu/log.py
index b8f0be35..01258945 100644
--- a/ryu/log.py
+++ b/ryu/log.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import gflags
 import inspect
diff --git a/ryu/ofproto/__init__.py b/ryu/ofproto/__init__.py
index 58736d4a..5d889369 100644
--- a/ryu/ofproto/__init__.py
+++ b/ryu/ofproto/__init__.py
@@ -1,16 +1,17 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 from . import ofproto_v1_0 as ofproto
diff --git a/ryu/ofproto/nx_match.py b/ryu/ofproto/nx_match.py
index 78a829d9..6c09ee7a 100644
--- a/ryu/ofproto/nx_match.py
+++ b/ryu/ofproto/nx_match.py
@@ -2,17 +2,18 @@
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 # Copyright (C) 2012 Simon Horman <horms ad verge net au>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import struct
 
diff --git a/ryu/ofproto/ofproto_parser.py b/ryu/ofproto/ofproto_parser.py
index b8a75c66..93c0d8f9 100644
--- a/ryu/ofproto/ofproto_parser.py
+++ b/ryu/ofproto/ofproto_parser.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 import struct
diff --git a/ryu/ofproto/ofproto_v1_0.py b/ryu/ofproto/ofproto_v1_0.py
index e666ad93..fd272a39 100644
--- a/ryu/ofproto/ofproto_v1_0.py
+++ b/ryu/ofproto/ofproto_v1_0.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 from struct import calcsize
 
diff --git a/ryu/ofproto/ofproto_v1_0_parser.py b/ryu/ofproto/ofproto_v1_0_parser.py
index 13d5688d..b262e5cf 100644
--- a/ryu/ofproto/ofproto_v1_0_parser.py
+++ b/ryu/ofproto/ofproto_v1_0_parser.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import collections
 import struct
diff --git a/ryu/ofproto/ofproto_v1_2.py b/ryu/ofproto/ofproto_v1_2.py
index e23108c2..4b9906e0 100644
--- a/ryu/ofproto/ofproto_v1_2.py
+++ b/ryu/ofproto/ofproto_v1_2.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 from struct import calcsize
 
diff --git a/ryu/ofproto/ofproto_v1_2_parser.py b/ryu/ofproto/ofproto_v1_2_parser.py
index 23a86956..3d0fe08c 100644
--- a/ryu/ofproto/ofproto_v1_2_parser.py
+++ b/ryu/ofproto/ofproto_v1_2_parser.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import collections
 import struct
diff --git a/ryu/utils.py b/ryu/utils.py
index 304f82c1..3a7b509d 100644
--- a/ryu/utils.py
+++ b/ryu/utils.py
@@ -1,17 +1,19 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 
 import inspect
 import logging
diff --git a/setup.py b/setup.py
index 0952a0fc..c13850b2 100644
--- a/setup.py
+++ b/setup.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
 # Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
 #
-# 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, version 3 of the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# 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.
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 
@@ -29,7 +30,7 @@ setup(name='ryu',
       url='http://www.osrg.net/ryu/',
 #      author='',
       author_email='ryu-devel@lists.sourceforge.net',
-      license='GPL v3 only',
+      license='Apache License 2.0',
       packages=find_packages(),
       scripts=['bin/ryu-manager',
                'bin/ryu-client'],