diff --git a/.travis.yml b/.travis.yml
index c78c2b2f..6f0243fe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,27 +1,63 @@
+#
+#   Copyright 2015 Pixar
+#
+#   Licensed under the Apache License, Version 2.0 (the "Apache License")
+#   with the following modification; you may not use this file except in
+#   compliance with the Apache License and the following modification to it:
+#   Section 6. Trademarks. is deleted and replaced with:
+#
+#   6. Trademarks. This License does not grant permission to use the trade
+#      names, trademarks, service marks, or product names of the Licensor
+#      and its affiliates, except as required to comply with Section 4(c) of
+#      the License and to reproduce the content of the NOTICE file.
+#
+#   You may obtain a copy of the Apache License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the Apache License with the above modification is
+#   distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+#   KIND, either express or implied. See the Apache License for the specific
+#   language governing permissions and limitations under the Apache License.
+#
 language: cpp
 
 branches:
   only:
    - dev
 
+# build environment
 before_script:
+   # as of 4/28/2015, travis worker has pre-installed cmake 2.8.7.
+   # opensubdiv needs 2.8.8 or later.
+   # get the latest cmake from PPA
    - cmake --version
    - sudo add-apt-repository --yes ppa:dcthomp/smtk
    - sudo apt-get update -qq
+   # remove existing cmake
    - sudo dpkg -r cmake cmake-data
-   - sudo apt-get install cmake   # update cmake to 3.x
+   # install newer version
+   - sudo apt-get install cmake
    - cmake --version
+
+   # install GL related libs from utopic
    - sudo add-apt-repository 'deb http://us.archive.ubuntu.com/ubuntu/ utopic main restricted universe multiverse'
    - sudo add-apt-repository 'deb http://us.archive.ubuntu.com/ubuntu/ utopic-updates main restricted universe multiverse'
    - sudo apt-get update -qq
+   # install glut and xxf86vm (for GL libs)
    - sudo apt-get install freeglut3-dev
    - sudo apt-get install libxxf86vm-dev
+   # install GLEW
    - sudo apt-get install libglew-dev
+   # install GLFW3
    - sudo apt-get install libglfw3-dev
-   - sudo apt-get install xvfb    # for GLtests... not working though.
+
+   # hopefully we'd like to test basic imaging tests too, using X virtual framebuffer
+   # (not working now)
+   - sudo apt-get install xvfb
 
 script:
-   - cmake --version
    - mkdir build && cd build
    - cmake -DNO_TBB=1 -DNO_OMP=1 -DNO_CUDA=1 -DNO_OPENCL=1 -DNO_MAYA=1 -DNO_PTEX=1 -DNO_GLTESTS=1 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ..
    - make