diff --git a/CMakeLists.txt b/CMakeLists.txt
index 83072ee29..754d3c966 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,7 @@ set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 include(InstallSymlink)
 include(MacroEnsureOutOfSourceBuild)
 include(dsym)
+include(xcproj)
 
 MACRO_ENSURE_OUT_OF_SOURCE_BUILD()
 
diff --git a/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/SDKSettings.plist b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/SDKSettings.plist
new file mode 100644
index 000000000..abe4f706a
--- /dev/null
+++ b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/SDKSettings.plist
@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>AlternateSDK</key>
+	<string>macosx10.13</string>
+	<key>CanonicalName</key>
+	<string>macosx.internal</string>
+	<key>CustomProperties</key>
+	<dict>
+		<key>KERNEL_EXTENSION_HEADER_SEARCH_PATHS</key>
+		<string>$(KERNEL_FRAMEWORK)/PrivateHeaders $(KERNEL_FRAMEWORK_HEADERS)</string>
+	</dict>
+	<key>DefaultProperties</key>
+	<dict>
+		<key>MACOSX_DEPLOYMENT_TARGET</key>
+		<string>10.13</string>
+		<key>PLATFORM_NAME</key>
+		<string>macosx</string>
+		<key>DEFAULT_KEXT_INSTALL_PATH</key>
+		<string>$(LIBRARY_KEXT_INSTALL_PATH)</string>
+	</dict>
+	<key>DisplayName</key>
+	<string>macosx.internal</string>
+	<key>MaximumDeploymentTarget</key>
+	<string>10.13</string>
+	<key>MinimalDisplayName</key>
+	<string>macosx.internal</string>
+	<key>MinimumSupportedToolsVersion</key>
+	<string>3.2</string>
+	<key>SupportedBuildToolComponents</key>
+	<array>
+		<string>com.apple.compilers.gcc.headers.4_2</string>
+	</array>
+	<key>Version</key>
+	<string>macosx.internal</string>
+	<key>isBaseSDK</key>
+	<string>YES</string>
+</dict>
+</plist>
diff --git a/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/System b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/System
new file mode 120000
index 000000000..1018d6597
--- /dev/null
+++ b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/System
@@ -0,0 +1 @@
+../MacOSX.sdk/System/
\ No newline at end of file
diff --git a/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/usr b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/usr
new file mode 120000
index 000000000..c2e159d98
--- /dev/null
+++ b/Developer/Platforms/MacOSX.platform/Developer/SDKs/macosx.internal.sdk/usr
@@ -0,0 +1 @@
+../MacOSX.sdk/usr
\ No newline at end of file
diff --git a/cmake/xcproj.cmake b/cmake/xcproj.cmake
index 2d6388270..342ca81fc 100644
--- a/cmake/xcproj.cmake
+++ b/cmake/xcproj.cmake
@@ -1,3 +1,11 @@
+# Create developer dir symlinks
+
+add_custom_target(xcproj_symlinks
+	DEPENDS Foundation
+	COMMAND env BUILD=${CMAKE_BUID_DIR} ${CMAKE_SOURCE_DIR}/Developer/symlinks.sh
+	WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/Developer
+)
+
 function(xcproj)
 	set(options)
 	set(oneValueArgs PROJECT)
@@ -6,21 +14,27 @@ function(xcproj)
 
 	set(product_dir ${CMAKE_CURRENT_BINARY_DIR}/Build/Products/Release)
 	
-	foreach(executable ${xcproj_EXECUTABLES})
+	foreach(executable IN LISTS xcproj_EXECUTABLES)
 		set(output ${output} ${product_dir}/${executable})
 	endforeach()
 
-	foreach(library ${xcproj_LIBRARIES})
+	foreach(library IN LISTS xcproj_LIBRARIES)
 		set(output ${output} ${product_dir}/${library}.dylib)
 	endforeach()
 
-	foreach(framework ${xcproj_FRAMEWORKS})
+	foreach(framework IN LISTS xcproj_FRAMEWORKS)
 		set(output ${output} ${product_dir}/${framework}.framework/${framework})
 	endforeach()
 
 	add_custom_command(
 		OUTPUT ${output}
-		COMMAND env RUNTIME_SPEC_PATH=${CMAKE_SOURCE_DIR}/src/external/xcbuild/Specifications/ DEVELOPER_DIR=${CMAKE_SOURCE_DIR}/Developer/ ${CMAKE_BINARY_DIR}/src/external/xcbuild/xcodebuild -project ${xcproj_PROJECT}
-		DEPENDS xcbuild
+		COMMAND env RUNTIME_SPEC_PATH=${CMAKE_SOURCE_DIR}/src/external/xcbuild/Specifications DEVELOPER_DIR=${CMAKE_SOURCE_DIR}/Developer ${CMAKE_BINARY_DIR}/src/external/xcbuild/Libraries/xcdriver/xcodebuild -project ${CMAKE_CURRENT_SOURCE_DIR}/${xcproj_PROJECT} -derivedDataPath ${CMAKE_CURRENT_BINARY_DIR}
+		DEPENDS xcbuild xcproj_symlinks
 	)
+
+	foreach(framework IN LISTS xcproj_FRAMEWORKS)
+		add_custom_target(${framework} ALL
+			DEPENDS ${product_dir}/${framework}.framework/${framework}
+		)
+	endforeach()
 endfunction(xcproj)
diff --git a/src/external/WebCore b/src/external/WebCore
index 4a09ca214..b66caa181 160000
--- a/src/external/WebCore
+++ b/src/external/WebCore
@@ -1 +1 @@
-Subproject commit 4a09ca214fb326e10179f8d09d04ce9e72790abc
+Subproject commit b66caa181b4d359cc5beeabc9f8291ab7d6ddd12
diff --git a/src/external/xcbuild b/src/external/xcbuild
index 6fd4b6ecc..14a8af687 160000
--- a/src/external/xcbuild
+++ b/src/external/xcbuild
@@ -1 +1 @@
-Subproject commit 6fd4b6ecc01f9f16ba589be88cabb8ed0eed93e8
+Subproject commit 14a8af687a43d11c754f97879a7a03cb5de7a511