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+CMAKE_VERSION
+-------------
+
+The CMake version string as three non-negative integer components
+separated by ``.`` and possibly followed by ``-`` and other information.
+The first two components represent the feature level and the third
+component represents either a bug-fix level or development date.
+
+Release versions and release candidate versions of CMake use the format::
+
+  <major>.<minor>.<patch>[-rc<n>]
+
+where the ``<patch>`` component is less than ``20000000``.  Development
+versions of CMake use the format::
+
+  <major>.<minor>.<date>[-<id>]
+
+where the ``<date>`` component is of format ``CCYYMMDD`` and ``<id>``
+may contain arbitrary text.  This represents development as of a
+particular date following the ``<major>.<minor>`` feature release.
+
+Individual component values are also available in variables:
+
+* :variable:`CMAKE_MAJOR_VERSION`
+* :variable:`CMAKE_MINOR_VERSION`
+* :variable:`CMAKE_PATCH_VERSION`
+* :variable:`CMAKE_TWEAK_VERSION`
+
+Use the :command:`if` command ``VERSION_LESS``, ``VERSION_GREATER``,
+``VERSION_EQUAL``, ``VERSION_LESS_EQUAL``, or ``VERSION_GREATER_EQUAL``
+operators to compare version string values against ``CMAKE_VERSION`` using a
+component-wise test.  Version component values may be 10 or larger so do not
+attempt to compare version strings as floating-point numbers.
+
+.. note::
+
+  CMake versions 2.8.2 through 2.8.12 used three components for the
+  feature level.  Release versions represented the bug-fix level in a
+  fourth component, i.e. ``<major>.<minor>.<patch>[.<tweak>][-rc<n>]``.
+  Development versions represented the development date in the fourth
+  component, i.e. ``<major>.<minor>.<patch>.<date>[-<id>]``.
+
+  CMake versions prior to 2.8.2 used three components for the
+  feature level and had no bug-fix component.  Release versions
+  used an even-valued second component, i.e.
+  ``<major>.<even-minor>.<patch>[-rc<n>]``.  Development versions
+  used an odd-valued second component with the development date as
+  the third component, i.e. ``<major>.<odd-minor>.<date>``.
+
+  The ``CMAKE_VERSION`` variable is defined by CMake 2.6.3 and higher.
+  Earlier versions defined only the individual component variables.