diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index 734296e..caf1d48 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -131,7 +131,7 @@
   * \endcode
   * Here, the problem is that operator new is not aware of the compile time alignment requirement of the
   * type Vector4f (and hence of the type Foo). Therefore "new Foo" does not necessarily returned a 16 bytes
-  * aligned pointer. The purpose of the class WithAlignedOperatorNew is exacly to overcome this issue, by
+  * aligned pointer. The purpose of the class WithAlignedOperatorNew is exactly to overcome this issue, by
   * overloading the operator new to return aligned data when the vectorization is enabled.
   * Here is a similar safe example:
   * \code
diff --git a/demos/opengl/CMakeLists.txt b/demos/opengl/CMakeLists.txt
index 8fd0255..06b4945 100644
--- a/demos/opengl/CMakeLists.txt
+++ b/demos/opengl/CMakeLists.txt
@@ -1,17 +1,20 @@
 
-FIND_PACKAGE(Qt4 REQUIRED)
+find_package(Qt4 REQUIRED)
+find_package(OpenGL REQUIRED)
 
 set(QT_USE_QTOPENGL TRUE)
 include(${QT_USE_FILE})
 
-SET(CMAKE_INCLUDE_CURRENT_DIR ON)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
-INCLUDE_DIRECTORIES( ${QT_INCLUDE_DIR} )
+include_directories( ${QT_INCLUDE_DIR} )
 
-SET(quaternion_demo_SRCS  gpuhelper.cpp camera.cpp trackball.cpp quaternion_demo.cpp)
+set(quaternion_demo_SRCS  gpuhelper.cpp camera.cpp trackball.cpp quaternion_demo.cpp)
 
-QT4_AUTOMOC(${quaternion_demo_SRCS})
+qt4_automoc(${quaternion_demo_SRCS})
 
-ADD_EXECUTABLE(quaternion_demo ${quaternion_demo_SRCS})
+add_executable(quaternion_demo ${quaternion_demo_SRCS})
 
-TARGET_LINK_LIBRARIES(quaternion_demo ${QT_QTCORE_LIBRARY} ${QT_QTGUI_LIBRARY}  ${QT_QTOPENGL_LIBRARY})
+target_link_libraries(quaternion_demo
+  ${QT_QTCORE_LIBRARY}    ${QT_QTGUI_LIBRARY}
+  ${QT_QTOPENGL_LIBRARY}  ${OPENGL_LIBRARIES} )
diff --git a/demos/opengl/gpuhelper.h b/demos/opengl/gpuhelper.h
index a3770aa..fd07d53 100644
--- a/demos/opengl/gpuhelper.h
+++ b/demos/opengl/gpuhelper.h
@@ -71,7 +71,7 @@
         GLenum matrixTarget);
 
     /** Make the matrix \a matrixTarget the current OpenGL matrix target.
-        Call this function before loadMatrix() or multMatrix() if you cannot guarrantee that glMatrixMode()
+        Call this function before loadMatrix() or multMatrix() if you cannot guarantee that glMatrixMode()
         has never been called after the last loadMatrix() or multMatrix() calls.
         \todo provides a debug mode checking the sanity of the cached matrix mode.
     */