Commented my understanding of the basic CMake tutorial to the best of my ability.

CMakeLists.txt

@@ -1,15 +1,68 @@
-cmake_minimum_required (VERSION 2.6)
-project(tutorial)
-set (tutorial_VERSION_MAJOR 1)
-set (tutorial_VERSION_MINOR 0)
+#
+# Cmake Tutorial
+#
+# This is a working example of the tutorial from the CMake website.  It
+# isn't intended to be anything more than that.
+#
 
+# Specify what versions of Cmake we support.
+#
+cmake_minimum_required (VERSION 2.6)
+
+# Enables the use of VERSION inside the project() function.
+#
+cmake_policy (SET CMP0048 NEW)
+
+# Specify the name of the project.  This results in the following
+# variables being set and available for use later.
+#
+# PROJECT_NAME, PROJECT_SOURCE_DIR, ${PROJECT_NAME}_SOURCE_DIR,
+# PROJECT_BINARY_DIR, ${PROJECT_NAME}_BINARY_DIR
+#
+project(tutorial VERSION 1.1 LANGUAGES "CXX")
+#
+# 'project' takes arguments, 'VERSION' and 'LANGUAGE'.  See the
+# accompanying documentation.
+
+# These variables are set using the VERSION argument above.  This is an
+# alternative (older) variant.
+#
+set (tutorial_VERSION_MAJOR 1)
+set (tutorial_VERSION_MINOR 2)
+
+# Another way:
+#
+set (${PROJECT_NAME}_VERSION_MAJOR 1)
+set (${PROJECT_NAME}_VERSION_MINOR 4)
+
+#
+# As with Makefiles, "last declaration wins."
+#
+
+# Specify an option that can control future options.  This can also
+# modify the behavior inside ".in" configuration files in the project
+# proper, defining them and making them available to preprocessors.
+#
 option (USE_MYMATH "Use tutorial provided math implementation" ON)
 
+# Include a CMAKE module
+#
 include (CheckFunctionExists)
+
+# Specify extra libraries needed to make programs.  This must be
+# declared before check_function_exists() is called, or the linker will
+# fail when linking math functions.
+# 
 set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} "-lm")
+
+# Attempt to build a test program that links and dereferences these
+# functions.  If the build is successful, set the variable as an option.
+#
 check_function_exists (log HAVE_LOG)
 check_function_exists (exp HAVE_EXP)
 
+# Preprocess a configuration file, making simple textual substitutions.
+#
 configure_file (
     "${PROJECT_SOURCE_DIR}/tutorial_config.h.in"
     "${PROJECT_BINARY_DIR}/tutorial_config.h"
@@ -17,21 +70,43 @@ configure_file (
 
 include_directories("${PROJECT_BINARY_DIR}")
 
+# Define the executable to be build, along with the source dependencies.
+# 
 add_executable(tutorial tutorial.cpp)
+
+# Describe the installation destination.
+#
 install (TARGETS tutorial DESTINATION bin)
 install (FILES "${PROJECT_BINARY_DIR}/tutorial_config.h" DESTINATION include)
 
+# If the option is set above, include a subdirectory.  It will have its
+# own CMakeLists.txt file to describe how its contents are to be built.
+#
 if (USE_MYMATH)
     include_directories ("${PROJECT_SOURCE_DIR}/mathfunctions")
     add_subdirectory(mathfunctions)
     set (EXTRA_LIBS ${EXTRA_LIBS} mathfunctions)
+
+    # Ensure that the extra libraries are included as a requirement for
+    # a target.  This creates a dependency graph that must be resolved
+    # in the correct order.
+    #
+    target_link_libraries(${PROJECT_NAME} ${EXTRA_LIBS})
 endif (USE_MYMATH)
 
-target_link_libraries(tutorial ${EXTRA_LIBS})
-
+# Define basic unit tests that run a program and analyze the output for
+# very simple strings
+#
 include(CTest)
+
+# A basic test... does it run at all?
+#
 add_test (TutorialRuns tutorial 25)
 
+# A defined macro that tests the propertis of the results.  The first
+# argument to add_test and set_tests_properties is a token to identify
+# the test to the reviewer.
+#
 macro (do_test arg result)
     add_test (TutorialComp${arg} tutorial ${arg})
     set_tests_properties(TutorialComp${arg} PROPERTIES PASS_REGULAR_EXPRESSION ${result})