diff --git a/Foundation/include/Poco/AtomicCounter.h b/Foundation/include/Poco/AtomicCounter.h
index f8cdb731a..e5d44f0d5 100644
--- a/Foundation/include/Poco/AtomicCounter.h
+++ b/Foundation/include/Poco/AtomicCounter.h
@@ -24,7 +24,7 @@
 #if POCO_OS == POCO_OS_WINDOWS_NT
 	#include "Poco/UnWindows.h"
 #elif POCO_OS == POCO_OS_MAC_OS_X
-	#if __MAC_OS_X_VERSION_MAX_ALLOWED >= __MAC_10_12 || __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0 || __TV_OS_VERSION_MAX_ALLOWED >= __TVOS_10_0 || __WATCH_OS_VERSION_MAX_ALLOWED >= __WATCHOS_3_0
+	#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 101200 || __IPHONE_OS_VERSION_MAX_ALLOWED >= 100000 || __TV_OS_VERSION_MAX_ALLOWED >= 100000 || __WATCH_OS_VERSION_MAX_ALLOWED >= 30000
 		#ifndef POCO_HAVE_STD_ATOMICS
 			#define POCO_HAVE_STD_ATOMICS
 		#endif
diff --git a/build/config/Darwin b/build/config/Darwin
index 7ae2baf65..62c26f724 100644
--- a/build/config/Darwin
+++ b/build/config/Darwin
@@ -1,12 +1,11 @@
 #
-# $Id: //poco/1.4/build/config/Darwin#6 $
+# $Id$
 #
 # Darwin
 #
-# Build settings for Mac OS X 10.6 or newer, using Clang.
-#
-# NOTE: This build configuration will build 64-bit binaries.
-# Use the Darwin32 build configuration to build 32-bit binaries.
+# Build settings for Mac OS X 10.9 (clang++, libc++, x86_64)
+# The build settings defined in this file are compatible
+# with XCode C++ projects.
 # 
 
 include $(POCO_BASE)/build/config/Darwin-clang-libc++
diff --git a/build/config/Darwin-clang b/build/config/Darwin-clang
index 26a1df86f..80df83397 100644
--- a/build/config/Darwin-clang
+++ b/build/config/Darwin-clang
@@ -1,11 +1,9 @@
 #
-# $Id: //poco/1.4/build/config/Darwin-clang#4 $
+# $Id$
 #
-# Darwin
+# Darwin-clang
 #
-# Build settings for Mac OS X 10.6 (clang++)
-# The build settings defined in this file are compatible
-# with XCode 4 C++ projects.
+# Build settings for Mac OS X 10.7 (clang, libstdc++, x86_64)
 # 
 # NOTE: This build configuration will build 64-bit binaries.
 # Use the Darwin32-clang build configuration to build 32-bit binaries.
@@ -18,9 +16,10 @@ LINKMODE ?= SHARED
 
 POCO_TARGET_OSARCH ?= x86_64
 POCO_HOST_OSARCH   := $(POCO_TARGET_OSARCH)
-ARCHFLAGS          ?= -arch $(POCO_TARGET_OSARCH)
+ARCHFLAGS          ?= -arch $(POCO_TARGET_OSARCH) 
+OSFLAGS            ?= -mmacosx-version-min=10.7
 
-OPENSSL_DIR        ?= /usr/local/opt/openssl/
+OPENSSL_DIR        ?= /usr/local/opt/openssl
 
 ifeq ($(POCO_TARGET_OSARCH),i386)
 RORELOCS = -read_only_relocs suppress
@@ -53,11 +52,11 @@ SHAREDLIBLINKEXT = .dylib
 #
 # Compiler and Linker Flags
 #
-CFLAGS          = $(ARCHFLAGS)
-CXXFLAGS        = $(ARCHFLAGS) -Wall -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-unneeded-internal-declaration
-LINKFLAGS       = $(ARCHFLAGS)
-SHLIBFLAGS      = $(ARCHFLAGS)
-DYLIBFLAGS      = $(ARCHFLAGS)
+CFLAGS          = $(ARCHFLAGS) $(OSFLAGS)
+CXXFLAGS        = $(ARCHFLAGS) $(OSFLAGS) -std=c++03 -stdlib=libstdc++ -Wall -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-unneeded-internal-declaration
+LINKFLAGS       = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libstdc++
+SHLIBFLAGS      = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libstdc++
+DYLIBFLAGS      = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libstdc++
 STATICOPT_CC    =
 STATICOPT_CXX   =
 STATICOPT_LINK  =
@@ -79,4 +78,4 @@ SYSFLAGS = -DPOCO_HAVE_IPv6 -DPOCO_NO_STAT64 -I$(OPENSSL_DIR)/include
 #
 # System Specific Libraries
 #
-SYSLIBS  = -L$(OPENSSL_DIR)/lib -ldl
+SYSLIBS  = -L$(OPENSSL_DIR)/lib -ldl 
diff --git a/build/config/Darwin-clang-libc++ b/build/config/Darwin-clang-libc++
index 781decdd8..29015b882 100644
--- a/build/config/Darwin-clang-libc++
+++ b/build/config/Darwin-clang-libc++
@@ -1,14 +1,14 @@
 #
-# $Id: //poco/1.4/build/config/Darwin-clang#4 $
+# $Id$
 #
-# Darwin
+# Darwin-clang-libc++
 #
-# Build settings for Mac OS X 10.6 (clang++)
+# Build settings for Mac OS X 10.9 (clang, libc++, x86_64)
 # The build settings defined in this file are compatible
-# with XCode 4 C++ projects.
+# with XCode C++ projects.
 # 
 # NOTE: This build configuration will build 64-bit binaries.
-# Use the Darwin32-clang build configuration to build 32-bit binaries.
+# Use the Darwin32-clang-libc++ build configuration to build 32-bit binaries.
 #
 
 #
@@ -19,8 +19,9 @@ LINKMODE ?= SHARED
 POCO_TARGET_OSARCH ?= x86_64
 POCO_HOST_OSARCH   := $(POCO_TARGET_OSARCH)
 ARCHFLAGS          ?= -arch $(POCO_TARGET_OSARCH) 
+OSFLAGS            ?= -mmacosx-version-min=10.9
 
-OPENSSL_DIR        ?= /usr/local/opt/openssl/
+OPENSSL_DIR        ?= /usr/local/opt/openssl
 
 ifeq ($(POCO_TARGET_OSARCH),i386)
 RORELOCS = -read_only_relocs suppress
@@ -53,11 +54,11 @@ SHAREDLIBLINKEXT = .dylib
 #
 # Compiler and Linker Flags
 #
-CFLAGS          = $(ARCHFLAGS)
-CXXFLAGS        = $(ARCHFLAGS) -std=c++11 -stdlib=libc++ -Wall -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-unneeded-internal-declaration
-LINKFLAGS       = $(ARCHFLAGS) -stdlib=libc++
-SHLIBFLAGS      = $(ARCHFLAGS) -stdlib=libc++
-DYLIBFLAGS      = $(ARCHFLAGS) -stdlib=libc++
+CFLAGS          = $(ARCHFLAGS) $(OSFLAGS)
+CXXFLAGS        = $(ARCHFLAGS) $(OSFLAGS) -std=c++11 -stdlib=libc++ -Wall -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-unneeded-internal-declaration
+LINKFLAGS       = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libc++
+SHLIBFLAGS      = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libc++
+DYLIBFLAGS      = $(ARCHFLAGS) $(OSFLAGS) -stdlib=libc++
 STATICOPT_CC    =
 STATICOPT_CXX   =
 STATICOPT_LINK  =
diff --git a/build/config/Darwin-gcc b/build/config/Darwin-gcc
deleted file mode 100644
index 99f295a3a..000000000
--- a/build/config/Darwin-gcc
+++ /dev/null
@@ -1,77 +0,0 @@
-#
-# $Id: //poco/1.4/build/config/Darwin-gcc#1 $
-#
-# Darwin
-#
-# Build settings for Mac OS X 10.6 (GCC 4.2)
-# The build settings defined in this file are compatible
-# with XCode 3.2.5 C++ projects.
-#
-# NOTE: This build configuration will build 64-bit binaries.
-# Use the Darwin32 build configuration to build 32-bit binaries.
-# 
-
-#
-# General Settings
-#
-LINKMODE ?= SHARED
-
-POCO_TARGET_OSARCH ?= x86_64
-POCO_HOST_OSARCH   := $(POCO_TARGET_OSARCH)
-ARCHFLAGS          ?= -arch $(POCO_TARGET_OSARCH)
-
-
-#
-# Tools
-#
-CC      = gcc
-CXX     = g++
-LINK    = $(CXX) -bind_at_load
-LIB     = libtool -static -o
-RANLIB  = ranlib
-SHLIB   = $(CXX) -dynamiclib -Wl,-install_name,$(POCO_LIB_INSTALLDIR)/$(notdir \$@) -o $@
-DYLIB   = $(CXX) -dynamic -bundle -bind_at_load -o $@ 
-SHLIBLN = $(POCO_BASE)/build/script/shlibln
-STRIP   = 
-DEP     = $(POCO_BASE)/build/script/makedepend.gcc
-SHELL   = sh
-RM      = rm -rf
-CP      = cp
-MKDIR   = mkdir -p
-
-#
-# Extension for Shared Libraries
-#
-SHAREDLIBEXT     = .$(target_version).dylib
-SHAREDLIBLINKEXT = .dylib
-
-#
-# Compiler and Linker Flags
-#
-CFLAGS          = $(ARCHFLAGS)
-CXXFLAGS        = $(ARCHFLAGS) -Wall -Wno-sign-compare
-LINKFLAGS       = $(ARCHFLAGS)
-SHLIBFLAGS      = $(ARCHFLAGS)
-DYLIBFLAGS      = $(ARCHFLAGS)
-STATICOPT_CC    =
-STATICOPT_CXX   =
-STATICOPT_LINK  =
-SHAREDOPT_CC    = -fPIC 
-SHAREDOPT_CXX   = -fPIC
-SHAREDOPT_LINK  = 
-DEBUGOPT_CC     = -O0 -g -gdwarf-2 -D_DEBUG=$(DEBUGLEVEL)
-DEBUGOPT_CXX    = -O0 -g -gdwarf-2 -D_DEBUG=$(DEBUGLEVEL) -mfix-and-continue -fvisibility-inlines-hidden -fasm-blocks
-DEBUGOPT_LINK   =
-RELEASEOPT_CC   = -DNDEBUG -Os
-RELEASEOPT_CXX  = -DNDEBUG -Os -fvisibility-inlines-hidden -fasm-blocks
-RELEASEOPT_LINK =
-
-#
-# System Specific Flags
-#
-SYSFLAGS = -DPOCO_HAVE_IPv6
-
-#
-# System Specific Libraries
-#
-SYSLIBS  = -ldl
diff --git a/build/config/Darwin32 b/build/config/Darwin32
index 84f594158..4e94353d1 100644
--- a/build/config/Darwin32
+++ b/build/config/Darwin32
@@ -1,14 +1,14 @@
 #
-# $Id: //poco/1.4/build/config/Darwin32#2 $
+# $Id$
 #
 # Darwin32
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 32-bits
+# Build settings for Mac OS X 10.9 (clang, libc++, i386)
 # The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# with XCode C++ projects.
 # 
 
 ARCHFLAGS = -arch i386
 POCO_TARGET_OSARCH = i386
 
-include $(POCO_BASE)/build/config/Darwin-clang
+include $(POCO_BASE)/build/config/Darwin-clang-libc++
diff --git a/build/config/Darwin32-clang b/build/config/Darwin32-clang
index 1a2110529..f624d805e 100644
--- a/build/config/Darwin32-clang
+++ b/build/config/Darwin32-clang
@@ -1,11 +1,9 @@
 #
-# $Id: //poco/1.4/build/config/Darwin32-clang#1 $
+# $Id$
 #
-# Darwin32
+# Darwin32-clang
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 32-bits
-# The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# Build settings for Mac OS X 10.7 (clang, libstdc++, i386)
 # 
 
 ARCHFLAGS = -arch i386
diff --git a/build/config/Darwin32-clang-libc++ b/build/config/Darwin32-clang-libc++
index 72859e4d7..eab0ebefd 100644
--- a/build/config/Darwin32-clang-libc++
+++ b/build/config/Darwin32-clang-libc++
@@ -1,11 +1,11 @@
 #
-# $Id: //poco/1.4/build/config/Darwin32-clang#1 $
+# $Id$
 #
-# Darwin32
+# Darwin32-clang-libc++
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 32-bits
+# Build settings for Mac OS X 10.9 (clang, libc++, i386)
 # The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# with XCode C++ projects.
 # 
 
 ARCHFLAGS = -arch i386
diff --git a/build/config/Darwin32-gcc b/build/config/Darwin32-gcc
deleted file mode 100644
index f426de604..000000000
--- a/build/config/Darwin32-gcc
+++ /dev/null
@@ -1,14 +0,0 @@
-#
-# $Id: //poco/1.4/build/config/Darwin32-gcc#1 $
-#
-# Darwin32
-#
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 32-bits
-# The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
-# 
-
-ARCHFLAGS = -arch i386
-POCO_TARGET_OSARCH = i386
-
-include $(POCO_BASE)/build/config/Darwin
diff --git a/build/config/Darwin64 b/build/config/Darwin64
index 985a083ab..92428622c 100644
--- a/build/config/Darwin64
+++ b/build/config/Darwin64
@@ -1,14 +1,14 @@
 #
-# $Id: //poco/1.4/build/config/Darwin64#2 $
+# $Id$
 #
 # Darwin64
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 64-bits
+# Build settings for Mac OS X 10.9 (clang, libc++, x86_64)
 # The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# with XCode C++ projects.
 # 
 
 ARCHFLAGS = -arch x86_64
 POCO_TARGET_OSARCH = x86_64
 
-include $(POCO_BASE)/build/config/Darwin-clang
+include $(POCO_BASE)/build/config/Darwin-clang-libc++
diff --git a/build/config/Darwin64-clang b/build/config/Darwin64-clang
index 36828b0fe..c1a258df1 100644
--- a/build/config/Darwin64-clang
+++ b/build/config/Darwin64-clang
@@ -1,11 +1,9 @@
 #
-# $Id: //poco/1.4/build/config/Darwin64-clang#1 $
+# $Id$
 #
-# Darwin64
+# Darwin64-clang
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 64-bits
-# The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# Build settings for Mac OS X 10.7 (clang, libstdc++, x86_64)
 # 
 
 ARCHFLAGS = -arch x86_64
diff --git a/build/config/Darwin64-clang-libc++ b/build/config/Darwin64-clang-libc++
index 9188b5586..32dacba49 100644
--- a/build/config/Darwin64-clang-libc++
+++ b/build/config/Darwin64-clang-libc++
@@ -1,11 +1,11 @@
 #
-# $Id: //poco/1.4/build/config/Darwin64-clang#1 $
+# $Id$
 #
-# Darwin64
+# Darwin64-clang-libc++
 #
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 64-bits
+# Build settings for Mac OS X 10.9 (clang, libc++, x86_64)
 # The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
+# with XCode C++ projects.
 # 
 
 ARCHFLAGS = -arch x86_64
diff --git a/build/config/Darwin64-gcc b/build/config/Darwin64-gcc
deleted file mode 100644
index b914eacef..000000000
--- a/build/config/Darwin64-gcc
+++ /dev/null
@@ -1,14 +0,0 @@
-#
-# $Id: //poco/1.4/build/config/Darwin64-gcc#1 $
-#
-# Darwin64
-#
-# Build settings for Mac OS X 10.5/10.6 (GCC 4.0.1), 64-bits
-# The build settings defined in this file are compatible
-# with XCode 3.1 C++ projects.
-# 
-
-ARCHFLAGS = -arch x86_64
-POCO_TARGET_OSARCH = x86_64
-
-include $(POCO_BASE)/build/config/Darwin