diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1fbbe08a1..77b460440 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,6 +11,9 @@
 #=============================================================================
 cmake_minimum_required(VERSION 2.8.2 FATAL_ERROR)
 set(CMAKE_LEGACY_CYGWIN_WIN32 0) # Remove when CMake >= 2.8.4 is required
+if(POLICY CMP0025)
+  cmake_policy(SET CMP0025 NEW)
+endif()
 project(CMake)
 
 if(CMAKE_BOOTSTRAP)
diff --git a/Modules/CMakeCCompilerId.c.in b/Modules/CMakeCCompilerId.c.in
index dda7bf6f3..6dde1c3b2 100644
--- a/Modules/CMakeCCompilerId.c.in
+++ b/Modules/CMakeCCompilerId.c.in
@@ -29,7 +29,12 @@
 # endif
 
 #elif defined(__clang__)
-# define COMPILER_ID "Clang"
+# if defined(__apple_build_version__)
+#  define COMPILER_ID "AppleClang"
+#  define COMPILER_VERSION_TWEAK DEC(__apple_build_version__)
+# else
+#  define COMPILER_ID "Clang"
+# endif
 # define COMPILER_VERSION_MAJOR DEC(__clang_major__)
 # define COMPILER_VERSION_MINOR DEC(__clang_minor__)
 # define COMPILER_VERSION_PATCH DEC(__clang_patchlevel__)
diff --git a/Modules/CMakeCXXCompilerId.cpp.in b/Modules/CMakeCXXCompilerId.cpp.in
index 915ae7faa..3a6092242 100644
--- a/Modules/CMakeCXXCompilerId.cpp.in
+++ b/Modules/CMakeCXXCompilerId.cpp.in
@@ -34,7 +34,12 @@
 # endif
 
 #elif defined(__clang__)
-# define COMPILER_ID "Clang"
+# if defined(__apple_build_version__)
+#  define COMPILER_ID "AppleClang"
+#  define COMPILER_VERSION_TWEAK DEC(__apple_build_version__)
+# else
+#  define COMPILER_ID "Clang"
+# endif
 # define COMPILER_VERSION_MAJOR DEC(__clang_major__)
 # define COMPILER_VERSION_MINOR DEC(__clang_minor__)
 # define COMPILER_VERSION_PATCH DEC(__clang_patchlevel__)
diff --git a/Modules/Compiler/AppleClang-ASM.cmake b/Modules/Compiler/AppleClang-ASM.cmake
new file mode 100644
index 000000000..f52bde05e
--- /dev/null
+++ b/Modules/Compiler/AppleClang-ASM.cmake
@@ -0,0 +1 @@
+include(Compiler/Clang-ASM)
diff --git a/Modules/Compiler/AppleClang-C.cmake b/Modules/Compiler/AppleClang-C.cmake
new file mode 100644
index 000000000..44070b83f
--- /dev/null
+++ b/Modules/Compiler/AppleClang-C.cmake
@@ -0,0 +1 @@
+include(Compiler/Clang-C)
diff --git a/Modules/Compiler/AppleClang-CXX.cmake b/Modules/Compiler/AppleClang-CXX.cmake
new file mode 100644
index 000000000..680f7208e
--- /dev/null
+++ b/Modules/Compiler/AppleClang-CXX.cmake
@@ -0,0 +1 @@
+include(Compiler/Clang-CXX)
diff --git a/Modules/Platform/Darwin-AppleClang-C.cmake b/Modules/Platform/Darwin-AppleClang-C.cmake
new file mode 100644
index 000000000..98971bbca
--- /dev/null
+++ b/Modules/Platform/Darwin-AppleClang-C.cmake
@@ -0,0 +1 @@
+include(Platform/Darwin-Clang-C)
diff --git a/Modules/Platform/Darwin-AppleClang-CXX.cmake b/Modules/Platform/Darwin-AppleClang-CXX.cmake
new file mode 100644
index 000000000..4e9e7c12e
--- /dev/null
+++ b/Modules/Platform/Darwin-AppleClang-CXX.cmake
@@ -0,0 +1 @@
+include(Platform/Darwin-Clang-CXX)
diff --git a/Source/cmDocumentVariables.cxx b/Source/cmDocumentVariables.cxx
index 8b5f8510b..58634ea13 100644
--- a/Source/cmDocumentVariables.cxx
+++ b/Source/cmDocumentVariables.cxx
@@ -1622,6 +1622,7 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
      "Possible values include:\n"
      "  Absoft = Absoft Fortran (absoft.com)\n"
      "  ADSP = Analog VisualDSP++ (analog.com)\n"
+     "  AppleClang = Apple Clang (apple.com)\n"
      "  Clang = LLVM Clang (clang.llvm.org)\n"
      "  Cray = Cray Compiler (cray.com)\n"
      "  Embarcadero, Borland = Embarcadero (embarcadero.com)\n"
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index dc4bf5053..eacf85ba2 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -624,6 +624,9 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
       {
       this->LanguageToOriginalSharedLibFlags[lang] = sharedLibFlags;
       }
+
+    // Translate compiler ids for compatibility.
+    this->CheckCompilerIdCompatibility(mf, lang);
     } // end for each language
 
   // Now load files that can override any settings on the platform or for
@@ -639,6 +642,44 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
     }
 }
 
+//----------------------------------------------------------------------------
+void cmGlobalGenerator::CheckCompilerIdCompatibility(cmMakefile* mf,
+                                                     std::string lang)
+{
+  std::string compilerIdVar = "CMAKE_" + lang + "_COMPILER_ID";
+  const char* compilerId = mf->GetDefinition(compilerIdVar.c_str());
+  if(compilerId && strcmp(compilerId, "AppleClang") == 0)
+    {
+    cmPolicies* policies = this->CMakeInstance->GetPolicies();
+    switch(mf->GetPolicyStatus(cmPolicies::CMP0025))
+      {
+      case cmPolicies::WARN:
+        if(!this->CMakeInstance->GetIsInTryCompile())
+          {
+          cmOStringStream w;
+          w << policies->GetPolicyWarning(cmPolicies::CMP0025) << "\n"
+            "Converting " << lang <<
+            " compiler id \"AppleClang\" to \"Clang\" for compatibility."
+            ;
+          mf->IssueMessage(cmake::AUTHOR_WARNING, w.str());
+          }
+      case cmPolicies::OLD:
+        // OLD behavior is to convert AppleClang to Clang.
+        mf->AddDefinition(compilerIdVar.c_str(), "Clang");
+        break;
+      case cmPolicies::REQUIRED_IF_USED:
+      case cmPolicies::REQUIRED_ALWAYS:
+        mf->IssueMessage(
+          cmake::FATAL_ERROR,
+          policies->GetRequiredPolicyError(cmPolicies::CMP0025)
+          );
+      case cmPolicies::NEW:
+        // NEW behavior is to keep AppleClang.
+        break;
+      }
+    }
+}
+
 //----------------------------------------------------------------------------
 const char*
 cmGlobalGenerator::GetLanguageOutputExtension(cmSourceFile const& source)
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 18aba24bf..70f6e32b2 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -383,6 +383,8 @@ private:
   void WriteSummary();
   void WriteSummary(cmTarget* target);
 
+  void CheckCompilerIdCompatibility(cmMakefile* mf, std::string lang);
+
   cmExternalMakefileProjectGenerator* ExtraGenerator;
 
   // track files replaced during a Generate
diff --git a/Source/cmPolicies.cxx b/Source/cmPolicies.cxx
index 9e5e6e004..1d3469f7f 100644
--- a/Source/cmPolicies.cxx
+++ b/Source/cmPolicies.cxx
@@ -620,6 +620,23 @@ cmPolicies::cmPolicies()
     "The NEW behavior for this policy is to not to allow including the "
     "result of an export() command.",
     2,8,13,0, cmPolicies::WARN);
+
+  this->DefinePolicy(
+    CMP0025, "CMP0025",
+    "Compiler id for Apple Clang is now AppleClang.",
+    "CMake >= 2.8.13 recognize that Apple Clang is a different compiler "
+    "than upstream Clang and that they have different version numbers.  "
+    "CMake now prefers to present this to projects by setting "
+    "CMAKE_<LANG>_COMPILER_ID to \"AppleClang\" instead of \"Clang\".  "
+    "However, existing projects may assume the compiler id for Apple Clang "
+    "is just \"Clang\" as it was in CMake < 2.8.13.  "
+    "Therefore this policy determines for Apple Clang which compiler id "
+    "to report in CMAKE_<LANG>_COMPILER_ID after <LANG> is enabled by "
+    "the project() or enable_language() command."
+    "\n"
+    "The OLD behavior for this policy is to use compiler id \"Clang\".  "
+    "The NEW behavior for this policy is to use compiler id \"AppleClang\".",
+    2,8,13,0, cmPolicies::WARN);
 }
 
 cmPolicies::~cmPolicies()
diff --git a/Source/cmPolicies.h b/Source/cmPolicies.h
index bafe5b2d3..ec8959d45 100644
--- a/Source/cmPolicies.h
+++ b/Source/cmPolicies.h
@@ -75,6 +75,7 @@ public:
     CMP0022, ///< INTERFACE_LINK_LIBRARIES defines the link interface
     CMP0023, ///< Disallow mixing keyword and plain tll signatures
     CMP0024, ///< Disallow including export() result.
+    CMP0025, ///< Compiler id for Apple Clang is now AppleClang
 
     /** \brief Always the last entry.
      *
diff --git a/Source/kwsys/CMakeLists.txt b/Source/kwsys/CMakeLists.txt
index 0f2783689..a9d89d474 100644
--- a/Source/kwsys/CMakeLists.txt
+++ b/Source/kwsys/CMakeLists.txt
@@ -85,6 +85,9 @@
 # written.
 
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6.3 FATAL_ERROR)
+IF(POLICY CMP0025)
+  CMAKE_POLICY(SET CMP0025 NEW)
+ENDIF()
 
 #-----------------------------------------------------------------------------
 # If a namespace is not specified, use "kwsys" and enable testing.
diff --git a/Tests/Assembler/CMakeLists.txt b/Tests/Assembler/CMakeLists.txt
index bb4bcccbe..1f07dc9cf 100644
--- a/Tests/Assembler/CMakeLists.txt
+++ b/Tests/Assembler/CMakeLists.txt
@@ -9,7 +9,7 @@ set(SRCS)
 # and also generate assembler files from C:
 if("${CMAKE_GENERATOR}" MATCHES "Makefile|Xcode" AND
     NOT CMAKE_OSX_ARCHITECTURES)
-  if(("${CMAKE_C_COMPILER_ID}" MATCHES "^(GNU|Clang|HP|SunPro|XL)$") OR ("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel"  AND  UNIX))
+  if(("${CMAKE_C_COMPILER_ID}" MATCHES "^(GNU|Clang|AppleClang|HP|SunPro|XL)$") OR ("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel"  AND  UNIX))
     set(C_FLAGS "${CMAKE_C_FLAGS}")
     separate_arguments(C_FLAGS)
     if(CMAKE_OSX_SYSROOT AND CMAKE_C_SYSROOT_FLAG AND NOT ";${C_FLAGS};" MATCHES ";${CMAKE_C_SYSROOT_FLAG};")
diff --git a/Tests/IncludeDirectories/CMakeLists.txt b/Tests/IncludeDirectories/CMakeLists.txt
index 35ad8dc90..9ee195714 100644
--- a/Tests/IncludeDirectories/CMakeLists.txt
+++ b/Tests/IncludeDirectories/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required (VERSION 2.6)
 project(IncludeDirectories)
 
 if (((CMAKE_C_COMPILER_ID STREQUAL GNU AND CMAKE_C_COMPILER_VERSION VERSION_GREATER 4.4)
-    OR CMAKE_C_COMPILER_ID STREQUAL Clang)
+    OR CMAKE_C_COMPILER_ID STREQUAL Clang OR CMAKE_C_COMPILER_ID STREQUAL AppleClang)
     AND (CMAKE_GENERATOR STREQUAL "Unix Makefiles" OR CMAKE_GENERATOR STREQUAL "Ninja"))
   include(CheckCXXCompilerFlag)
   check_cxx_compiler_flag(-Wunused-variable run_sys_includes_test)
diff --git a/Tests/RunCMake/RunCMake.cmake b/Tests/RunCMake/RunCMake.cmake
index f770c9368..5c7c05c1a 100644
--- a/Tests/RunCMake/RunCMake.cmake
+++ b/Tests/RunCMake/RunCMake.cmake
@@ -36,6 +36,9 @@ function(run_cmake test)
   if(NOT DEFINED RunCMake_TEST_OPTIONS)
     set(RunCMake_TEST_OPTIONS "")
   endif()
+  if(APPLE)
+    list(APPEND RunCMake_TEST_OPTIONS -DCMAKE_POLICY_DEFAULT_CMP0025=NEW)
+  endif()
   execute_process(
     COMMAND ${CMAKE_COMMAND} "${RunCMake_TEST_SOURCE_DIR}"
               -G "${RunCMake_GENERATOR}"
diff --git a/Utilities/cmcurl/CMakeLists.txt b/Utilities/cmcurl/CMakeLists.txt
index 74a713dd8..abf04d8b0 100644
--- a/Utilities/cmcurl/CMakeLists.txt
+++ b/Utilities/cmcurl/CMakeLists.txt
@@ -1,4 +1,7 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6.3 FATAL_ERROR)
+IF(POLICY CMP0025)
+  CMAKE_POLICY(SET CMP0025 NEW)
+ENDIF()
 PROJECT(LIBCURL C)
 
 # Setup package meta-data
diff --git a/Utilities/cmlibarchive/CMakeLists.txt b/Utilities/cmlibarchive/CMakeLists.txt
index 8ef0e89d6..132bfebdb 100644
--- a/Utilities/cmlibarchive/CMakeLists.txt
+++ b/Utilities/cmlibarchive/CMakeLists.txt
@@ -56,7 +56,7 @@ SET(CMAKE_REQUIRED_FLAGS)
 
 # Disable warnings to avoid changing 3rd party code.
 IF("${CMAKE_C_COMPILER_ID}" MATCHES
-    "^(GNU|Clang|XL|VisualAge|SunPro|MIPSpro|HP|Intel)$")
+    "^(GNU|Clang|AppleClang|XL|VisualAge|SunPro|MIPSpro|HP|Intel)$")
   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -w")
 ELSEIF("${CMAKE_C_COMPILER_ID}" MATCHES "^(PathScale)$")
   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -woffall")