diff --git a/Makefile b/Makefile
index 804e5e4..b5c2e4c 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,7 @@
 
 OBJROOT=.
 SYMROOT=.
+TRIPLE=-apple-
 
 installsrc:: $(SRCROOT)
 
diff --git a/include/__config b/include/__config
index 7b66dfc..a3518d9 100644
--- a/include/__config
+++ b/include/__config
@@ -37,7 +37,16 @@
 #endif
 
 #if !defined(_LIBCPP_LITTLE_ENDIAN) || !defined(_LIBCPP_BIG_ENDIAN)
-#error unable to determine endian
+# include <endian.h>
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#  define _LIBCPP_LITTLE_ENDIAN 1
+#  define _LIBCPP_BIG_ENDIAN    0
+# elif __BYTE_ORDER == __BIG_ENDIAN
+#  define _LIBCPP_LITTLE_ENDIAN 0
+#  define _LIBCPP_BIG_ENDIAN    1
+# else
+#  error unable to determine endian
+# endif
 #endif
 
 #ifndef _LIBCPP_VISIBILITY_TAG
diff --git a/include/__locale b/include/__locale
index 249e5b8..395cb26 100644
--- a/include/__locale
+++ b/include/__locale
@@ -18,6 +18,7 @@
 #include <mutex>
 #include <cstdint>
 #include <cctype>
+#include <locale.h>
 #include <xlocale.h>
 
 #pragma GCC system_header
@@ -294,6 +295,7 @@
 public:
     typedef __uint32_t mask;
 
+#if __APPLE__
     static const mask space  = _CTYPE_S;
     static const mask print  = _CTYPE_R;
     static const mask cntrl  = _CTYPE_C;
@@ -304,6 +306,18 @@
     static const mask punct  = _CTYPE_P;
     static const mask xdigit = _CTYPE_X;
     static const mask blank  = _CTYPE_B;
+#else  /* !__APPLE__ */
+    static const mask space  = _ISspace;
+    static const mask print  = _ISprint;
+    static const mask cntrl  = _IScntrl;
+    static const mask upper  = _ISupper;
+    static const mask lower  = _ISlower;
+    static const mask alpha  = _ISalpha;
+    static const mask digit  = _ISdigit;
+    static const mask punct  = _ISpunct;
+    static const mask xdigit = _ISxdigit;
+    static const mask blank  = _ISblank;
+#endif  /* __APPLE__ */
     static const mask alnum  = alpha | digit;
     static const mask graph  = alnum | punct;
 
@@ -507,7 +521,11 @@
 
     static locale::id id;
 
+#ifdef _CACHED_RUNES
     static const size_t table_size = _CACHED_RUNES;
+#else
+    static const size_t table_size = 256;  // FIXME: Don't hardcode this.
+#endif
     const mask* table() const throw() {return __tab_;}
     static const mask* classic_table() throw();
 
diff --git a/include/algorithm b/include/algorithm
index f3412f7..c53bf37 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -552,16 +552,12 @@
 #ifdef _LIBCPP_DEBUG
 #include <cassert>
 #endif
-//#include <cstdlib>
-#define RAND_MAX 0x7fffffff     // #include <cstdlib>
-extern "C" int rand(void);      // #include <cstdlib>
+#include <cstdlib>
 
 #pragma GCC system_header
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-using ::rand;                   // #include <cstdlib>
-
 template <class _T1, class _T2 = _T1>
 struct __equal_to
 {
diff --git a/include/cstddef b/include/cstddef
index 11d07a2..efe0f61 100644
--- a/include/cstddef
+++ b/include/cstddef
@@ -34,6 +34,8 @@
 */
 
 #include <__config>
+#define __need_ptrdiff_t
+#define __need_size_t
 #include <stddef.h>
 
 #pragma GCC system_header
diff --git a/include/iosfwd b/include/iosfwd
index e9a6a0f..32f679e 100644
--- a/include/iosfwd
+++ b/include/iosfwd
@@ -86,7 +86,7 @@
 */
 
 #include <__config>
-#include <_types.h>  // for __darwin_mbstate_t
+#include <wchar.h>  // for mbstate_t
 
 #pragma GCC system_header
 
@@ -153,11 +153,11 @@
 typedef basic_fstream<wchar_t>       wfstream;
 
 template <class _State>             class fpos;
-typedef fpos<__darwin_mbstate_t>    streampos;
-typedef fpos<__darwin_mbstate_t>    wstreampos;
+typedef fpos<mbstate_t>    streampos;
+typedef fpos<mbstate_t>    wstreampos;
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-typedef fpos<__darwin_mbstate_t>    u16streampos;
-typedef fpos<__darwin_mbstate_t>    u32streampos;
+typedef fpos<mbstate_t>    u16streampos;
+typedef fpos<mbstate_t>    u32streampos;
 #endif
 
 typedef long long streamoff;        // for char_traits in <string>
diff --git a/include/locale b/include/locale
index 284184f..09faccd 100644
--- a/include/locale
+++ b/include/locale
@@ -137,6 +137,9 @@
 #include <streambuf>
 #include <iterator>
 #include <limits>
+#if !__APPLE__
+#include <cstdarg>
+#endif
 #include <cstdlib>
 #include <ctime>
 #include <nl_types.h>
@@ -145,6 +148,131 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+// OSX has nice foo_l() functions that let you turn off use of the global
+// locale.  Linux, not so much.  The following functions avoid the locale when
+// that's possible and otherwise do the wrong thing.  FIXME.
+#if __APPLE__
+
+template <class _Tp>
+inline
+int
+__nolocale_sprintf(char* __restrict __str,
+                   const char* __restrict __format, _Tp __v)
+{
+    return sprintf_l(__str, 0, __format, __v);
+}
+
+template <class _Tp>
+inline
+int
+__nolocale_snprintf(char* __restrict __str, size_t __size,
+                    const char* __restrict __format, _Tp __v)
+{
+    return snprintf_l(__str, __size, 0, __format, __v);
+}
+
+template <class _Tp>
+inline
+int
+__nolocale_snprintf(char* __restrict __str, size_t __size,
+                    const char* __restrict __format, int __prec, _Tp __v)
+{
+    return snprintf_l(__str, __size, 0, __format, __prec, __v);
+}
+
+template <class _Tp>
+inline
+int
+__nolocale_asprintf(char** __ret, const char* __restrict __format, _Tp __v)
+{
+    return asprintf_l(__ret, 0, __format, __v);
+}
+
+template <class _Tp>
+inline
+int
+__nolocale_asprintf(char** __ret, const char* __restrict __format, int __prec,
+                                                                        _Tp __v)
+{
+    return asprintf_l(__ret, 0, __format, __prec, __v);
+}
+
+template <class _Tp>
+inline
+int
+__nolocale_sscanf(const char* __restrict __str,
+                  const char* __restrict __format, _Tp* __v)
+{
+    return sscanf_l(__str, 0, __format, __v);
+}
+
+inline
+int
+__nolocale_isxdigit(int __c)
+{
+    return isxdigit_l(__c, 0);
+}
+
+inline
+int
+__nolocale_isdigit(int __c)
+{
+    return isdigit_l(__c, 0);
+}
+
+#else  /* !__APPLE__ */
+inline int
+__nolocale_sprintf(char* __restrict __str,
+                   const char* __restrict __format, ...)
+{
+    va_list __ap;
+    va_start(__ap, __format);
+    int __result = vsprintf(__str, __format, __ap);
+    va_end(__ap);
+    return __result;
+}
+inline int
+__nolocale_snprintf(char* __restrict __str, size_t __size,
+                    const char* __restrict __format, ...)
+{
+    va_list __ap;
+    va_start(__ap, __format);
+    int __result = vsnprintf(__str, __size, __format, __ap);
+    va_end(__ap);
+    return __result;
+}
+inline int
+__nolocale_asprintf(char** __ret,
+                    const char* __restrict __format, ...)
+{
+    va_list __ap;
+    va_start(__ap, __format);
+    int __result = vasprintf(__ret, __format, __ap);
+    va_end(__ap);
+    return __result;
+}
+inline int
+__nolocale_sscanf(const char* __restrict __str,
+                  const char* __restrict __format, ...)
+{
+    va_list __ap;
+    va_start(__ap, __format);
+    int __result = vsscanf(__str, __format, __ap);
+    va_end(__ap);
+    return __result;
+}
+inline int
+__nolocale_isxdigit(int __c)
+{
+    return isxdigit(__c);
+}
+inline int
+__nolocale_isdigit(int __c)
+{
+    return isdigit(__c);
+}
+#endif  /* __APPLE__ */
+
 // __scan_keyword
 // Scans [__b, __e) until a match is found in the basic_strings range
 //  [__kb, __ke) or until it can be shown that there is no match in [__kb, __ke).
@@ -1002,7 +1130,7 @@
             break;
     // Stage 3
     __a[sizeof(__a)-1] = 0;
-    if (sscanf_l(__a, 0, "%p", &__v) != 1)
+    if (__nolocale_sscanf(__a, "%p", &__v) != 1)
         __err = ios_base::failbit;
     // EOF checked
     if (__b == __e)
@@ -1107,13 +1235,13 @@
         *__oe++ = __ct.widen(*__nf++);
         *__oe++ = __ct.widen(*__nf++);
         for (__ns = __nf; __ns < __ne; ++__ns)
-            if (!isxdigit_l(*__ns, 0))
+            if (!__nolocale_isxdigit(*__ns))
                 break;
     }
     else
     {
         for (__ns = __nf; __ns < __ne; ++__ns)
-            if (!isdigit_l(*__ns, 0))
+            if (!__nolocale_isdigit(*__ns))
                 break;
     }
     if (__grouping.empty())
@@ -1310,7 +1438,7 @@
                           + ((numeric_limits<long>::digits % 3) != 0)
                           + 1;
     char __nar[__nbuf];
-    int __nc = sprintf_l(__nar, 0, __fmt, __v);
+    int __nc = __nolocale_sprintf(__nar, __fmt, __v);
     char* __ne = __nar + __nc;
     char* __np = this->__identify_padding(__nar, __ne, __iob);
     // Stage 2 - Widen __nar while adding thousands separators
@@ -1336,7 +1464,7 @@
                           + ((numeric_limits<long long>::digits % 3) != 0)
                           + 1;
     char __nar[__nbuf];
-    int __nc = sprintf_l(__nar, 0, __fmt, __v);
+    int __nc = __nolocale_sprintf(__nar, __fmt, __v);
     char* __ne = __nar + __nc;
     char* __np = this->__identify_padding(__nar, __ne, __iob);
     // Stage 2 - Widen __nar while adding thousands separators
@@ -1362,7 +1490,7 @@
                           + ((numeric_limits<unsigned long>::digits % 3) != 0)
                           + 1;
     char __nar[__nbuf];
-    int __nc = sprintf_l(__nar, 0, __fmt, __v);
+    int __nc = __nolocale_sprintf(__nar, __fmt, __v);
     char* __ne = __nar + __nc;
     char* __np = this->__identify_padding(__nar, __ne, __iob);
     // Stage 2 - Widen __nar while adding thousands separators
@@ -1388,7 +1516,7 @@
                           + ((numeric_limits<unsigned long long>::digits % 3) != 0)
                           + 1;
     char __nar[__nbuf];
-    int __nc = sprintf_l(__nar, 0, __fmt, __v);
+    int __nc = __nolocale_sprintf(__nar, __fmt, __v);
     char* __ne = __nar + __nc;
     char* __np = this->__identify_padding(__nar, __ne, __iob);
     // Stage 2 - Widen __nar while adding thousands separators
@@ -1415,16 +1543,18 @@
     char* __nb = __nar;
     int __nc;
     if (__specify_precision)
-        __nc = snprintf_l(__nb, __nbuf, 0, __fmt, (int)__iob.precision(), __v);
+        __nc = __nolocale_snprintf(__nb, __nbuf, __fmt,
+                                   (int)__iob.precision(), __v);
     else
-        __nc = snprintf_l(__nb, __nbuf, 0, __fmt, __v);
+        __nc = __nolocale_snprintf(__nb, __nbuf, __fmt, __v);
     unique_ptr<char, void(*)(void*)> __nbh(0, free);
     if (__nc > static_cast<int>(__nbuf-1))
     {
         if (__specify_precision)
-            __nc = asprintf_l(&__nb, 0, __fmt, (int)__iob.precision(), __v);
+            __nc = __nolocale_asprintf(&__nb, __fmt, (int)__iob.precision(),
+                                       __v);
         else
-            __nc = asprintf_l(&__nb, 0, __fmt, __v);
+            __nc = __nolocale_asprintf(&__nb, __fmt, __v);
         if (__nb == 0)
             __throw_bad_alloc();
         __nbh.reset(__nb);
@@ -1465,16 +1595,18 @@
     char* __nb = __nar;
     int __nc;
     if (__specify_precision)
-        __nc = snprintf_l(__nb, __nbuf, 0, __fmt, (int)__iob.precision(), __v);
+        __nc = __nolocale_snprintf(__nb, __nbuf, __fmt,
+                                   (int)__iob.precision(), __v);
     else
-        __nc = snprintf_l(__nb, __nbuf, 0, __fmt, __v);
+        __nc = __nolocale_snprintf(__nb, __nbuf, __fmt, __v);
     unique_ptr<char, void(*)(void*)> __nbh(0, free);
     if (__nc > static_cast<int>(__nbuf-1))
     {
         if (__specify_precision)
-            __nc = asprintf_l(&__nb, 0, __fmt, (int)__iob.precision(), __v);
+            __nc = __nolocale_asprintf(&__nb, __fmt, (int)__iob.precision(),
+                                       __v);
         else
-            __nc = asprintf_l(&__nb, 0, __fmt, __v);
+            __nc = __nolocale_asprintf(&__nb, __fmt, __v);
         if (__nb == 0)
             __throw_bad_alloc();
         __nbh.reset(__nb);
@@ -1510,7 +1642,7 @@
     char __fmt[6] = "%p";
     const unsigned __nbuf = 20;
     char __nar[__nbuf];
-    int __nc = sprintf_l(__nar, 0, __fmt, __v);
+    int __nc = __nolocale_sprintf(__nar, __fmt, __v);
     char* __ne = __nar + __nc;
     char* __np = this->__identify_padding(__nar, __ne, __iob);
     // Stage 2 - Widen __nar
@@ -3162,7 +3294,7 @@
     // secure memory for digit storage
     if (__n > __bs-1)
     {
-        __n = asprintf_l(&__bb, 0, "%.0Lf", __units);
+        __n = __nolocale_asprintf(&__bb, "%.0Lf", __units);
         if (__bb == 0)
             __throw_bad_alloc();
         __hn.reset(__bb);
diff --git a/include/string b/include/string
index 6b11e02..15713f0 100644
--- a/include/string
+++ b/include/string
@@ -358,6 +358,7 @@
 #include <__config>
 #include <iosfwd>
 #include <cstring>
+#include <cstdio>  // For EOF.
 #include <cwchar>
 #include <algorithm>
 #include <iterator>
diff --git a/include/thread b/include/thread
index 3c1cf99..16faed9 100644
--- a/include/thread
+++ b/include/thread
@@ -115,6 +115,9 @@
 
 class __thread_id
 {
+    // FIXME: pthread_t is a pointer on Darwin but a long on Linux.
+    // NULL is the no-thread value on Darwin.  Someone needs to check
+    // on other platforms.  We assume 0 works everywhere for now.
     pthread_t __id_;
 
 public:
@@ -206,7 +209,7 @@
 
     void swap(thread& __t) {_STD::swap(__t_, __t.__t_);}
 
-    bool joinable() const {return __t_ != nullptr;}
+    bool joinable() const {return __t_ != 0;}
     void join();
     void detach();
     id get_id() const {return __t_;}
diff --git a/include/vector b/include/vector
index a85d39a..e97e939 100644
--- a/include/vector
+++ b/include/vector
@@ -1118,7 +1118,7 @@
         if (__n > __s)
             __construct_at_end(__n - __s, __u);
         else
-            __destruct_at_end(this->__begin_ + __n);
+            this->__destruct_at_end(this->__begin_ + __n);
     }
     else
     {
diff --git a/lib/buildit b/lib/buildit
index 6cbe971..43341f9 100755
--- a/lib/buildit
+++ b/lib/buildit
@@ -1,41 +1,60 @@
+#! /bin/sh
+#
+# Set the $TRIPLE environment variable to your system's triple before
+# running this script.  If you set $CXX, that will be used to compile
+# the library.  Otherwise we'll use g++.
+
+set -e
+
 if [ `basename $(pwd)` != "lib" ]
 then
 	echo "current directory must be lib"
 	exit 1
 fi
 
-if [ -z $CC ]
+if [ -z $CXX ]
 then
-	CC=g++
+	CXX=g++
 fi
 
+case $TRIPLE in
+  *-apple-*)
+    if [ -z $RC_BUILDIT ]
+    then
+      RC_CFLAGS="-arch i386 -arch ppc -arch x86_64"
+    fi
+    SOEXT=dylib
+    LDSHARED_FLAGS="-o libc++.1.dylib \
+        -dynamiclib -nodefaultlibs -current_version 1 \
+        -compatibility_version 1 \
+        -install_name /usr/lib/libc++.dylib \
+        -Wl,-reexport_library,/usr/lib/libc++abi.dylib \
+        /usr/lib/libSystem.B.dylib"
+    ;;
+  *)
+    RC_CFLAGS="-fPIC"
+    SOEXT=so
+    LDSHARED_FLAGS="-o libc++.so.1.0 \
+        -shared -nodefaultlibs -Wl,-soname,libc++.so.1 \
+        -lstdc++ -lc"
+    ;;
+esac
+
 if [ -z $RC_BUILDIT ]
 then
-	RC_CFLAGS="-arch i386 -arch ppc -arch x86_64"
-fi
-
-if [ -z $RC_BUILDIT ]
-then
-    rm libc++.1.dylib
+    rm -f libc++.1.$SOEXT*
 fi
 
 set -x
 
-for FILE in $(ls ../src/*.cpp); do
-	$CC -c -g -Os $RC_CFLAGS -nostdinc++ -I../include $FILE
+for FILE in ../src/*.cpp; do
+	$CXX -c -g -Os $RC_CFLAGS -nostdinc++ -I../include $FILE
 done
 
-$CC -dynamiclib -nodefaultlibs $RC_CFLAGS -current_version 1 \
-        -compatibility_version 1 \
-        -o libc++.1.dylib *.o \
-        -install_name /usr/lib/libc++.dylib \
-        -Wl,-reexport_library,/usr/lib/libc++abi.dylib \
-        /usr/lib/libSystem.B.dylib
+$CXX *.o $RC_CFLAGS $LDSHARED_FLAGS
 
 #libtool -static -o libc++.a *.o
 
-set +x
-
 if [ -z $RC_BUILDIT ]
 then
     rm *.o
diff --git a/src/chrono.cpp b/src/chrono.cpp
index b984f9d..d06fbf7 100644
--- a/src/chrono.cpp
+++ b/src/chrono.cpp
@@ -9,7 +9,13 @@
 
 #include "chrono"
 #include <sys/time.h>        //for gettimeofday and timeval
+#if __APPLE__
 #include <mach/mach_time.h>  // mach_absolute_time, mach_timebase_info_data_t
+#else  /* !__APPLE__ */
+#include <cerrno>  // errno
+#include <system_error>  // __throw_system_error
+#include <time.h>  // clock_gettime, CLOCK_MONOTONIC
+#endif  /* __APPLE__ */
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
@@ -40,6 +46,7 @@
 
 // monotonic_clock
 
+#if __APPLE__
 //   mach_absolute_time() * MachInfo.numer / MachInfo.denom is the number of
 //   nanoseconds since the computer booted up.  MachInfo.numer and MachInfo.denom
 //   are run time constants supplied by the OS.  This clock has no relationship
@@ -96,6 +103,26 @@
     return time_point(duration(fp()));
 }
 
+#else  /* !APPLE */
+// FIXME: We assume that clock_gettime(CLOCK_MONOTONIC) works on
+// non-apple systems.  Instead, we should check _POSIX_TIMERS and
+// _POSIX_MONOTONIC_CLOCK and fall back to something else if those
+// don't exist.
+
+// Warning:  If this is not truly monotonic, then it is non-conforming.  It is
+//  better for it to not exist and have the rest of libc++ use system_clock
+//  instead.
+
+monotonic_clock::time_point
+monotonic_clock::now()
+{
+    struct timespec tp;
+    if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
+        __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
+    return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
+}
+#endif  /* APPLE */
+
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/src/exception.cpp b/src/exception.cpp
index 336527d..e48e9c4 100644
--- a/src/exception.cpp
+++ b/src/exception.cpp
@@ -72,8 +72,11 @@
 	// on Darwin, there is a helper function so __cxa_get_globals is private
     return __cxxabiapple::__cxa_uncaught_exception();
 #else
-    __cxa_eh_globals * globals = __cxa_get_globals();
-    return (globals->uncaughtExceptions != 0);
+    #warning uncaught_exception not yet implemented
+    ::abort();
+    // Not provided by Ubuntu gcc-4.2.4's cxxabi.h.
+    // __cxa_eh_globals * globals = __cxa_get_globals();
+    // return (globals->uncaughtExceptions != 0);
 #endif
 }
 
@@ -168,4 +171,3 @@
 	::abort();
 #endif
 }
-
diff --git a/src/ios.cpp b/src/ios.cpp
index 3bf3cbc..4d1261e 100644
--- a/src/ios.cpp
+++ b/src/ios.cpp
@@ -106,7 +106,11 @@
 string
 __iostream_category::message(int ev) const
 {
-    if (ev != static_cast<int>(io_errc::stream) && ev <= ELAST)
+    if (ev != static_cast<int>(io_errc::stream)
+#ifdef ELAST
+        && ev <= ELAST
+#endif
+        )
         return __do_message::message(ev);
     return string("unspecified iostream_category error");
 }
diff --git a/src/locale.cpp b/src/locale.cpp
index e219d98..a65d6ed 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -17,10 +17,11 @@
 #include "cstring"
 #include "cwctype"
 #include "__sso_allocator"
-#include <libkern/OSAtomic.h>
 #include <langinfo.h>
 #include <stdlib.h>
 
+// FIXME: Locales are hard.
+#if __APPLE__
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace {
@@ -534,7 +535,7 @@
 void
 locale::id::__init()
 {
-    __id_ = OSAtomicIncrement32Barrier(&__next_id);
+    __id_ = __sync_add_and_fetch(&__next_id, 1);
 }
 
 // template <> class collate_byname<char>
@@ -3678,3 +3679,4 @@
 template class __vector_base_common<true>;
 
 _LIBCPP_END_NAMESPACE_STD
+#endif  /* __APPLE__ */
diff --git a/src/memory.cpp b/src/memory.cpp
index e3075bc..f35b838 100644
--- a/src/memory.cpp
+++ b/src/memory.cpp
@@ -8,7 +8,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "memory"
-#include <libkern/OSAtomic.h>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
@@ -16,57 +15,19 @@
 {
 
 template <class T>
-inline
-typename enable_if
-<
-    sizeof(T) * __CHAR_BIT__ == 32,
-    T
->::type
+inline T
 increment(T& t)
 {
-    return OSAtomicIncrement32Barrier((volatile int32_t*)&t);
+    return __sync_add_and_fetch(&t, 1);
 }
 
 template <class T>
-inline
-typename enable_if
-<
-    sizeof(T) * __CHAR_BIT__ == 32,
-    T
->::type
+inline T
 decrement(T& t)
 {
-    return OSAtomicDecrement32Barrier((volatile int32_t*)&t);
+    return __sync_add_and_fetch(&t, -1);
 }
 
-#ifndef __ppc__
-
-template <class T>
-inline
-typename enable_if
-<
-    sizeof(T) * __CHAR_BIT__ == 64,
-    T
->::type
-increment(T& t)
-{
-    return OSAtomicIncrement64Barrier((volatile int64_t*)&t);
-}
-
-template <class T>
-inline
-typename enable_if
-<
-    sizeof(T) * __CHAR_BIT__ == 64,
-    T
->::type
-decrement(T& t)
-{
-    return OSAtomicDecrement64Barrier((volatile int64_t*)&t);
-}
-
-#endif
-
 }  // namespace
 
 
@@ -134,9 +95,9 @@
     long object_owners = __shared_owners_;
     while (object_owners != -1)
     {
-        if (OSAtomicCompareAndSwapLongBarrier(object_owners,
-                                              object_owners+1,
-                                              &__shared_owners_))
+        if (__sync_bool_compare_and_swap(&__shared_owners_,
+                                         object_owners,
+                                         object_owners+1))
         {
             __add_weak();
             return this;
diff --git a/src/mutex.cpp b/src/mutex.cpp
index f98d725..7ea7349 100644
--- a/src/mutex.cpp
+++ b/src/mutex.cpp
@@ -148,7 +148,7 @@
 
 recursive_timed_mutex::recursive_timed_mutex()
     : __count_(0),
-      __id_(nullptr)
+      __id_(0)
 {
 }
 
@@ -197,7 +197,7 @@
     unique_lock<mutex> lk(__m_);
     if (--__count_ == 0)
     {
-        __id_ = nullptr;
+        __id_ = 0;
         lk.unlock();
         __cv_.notify_one();
     }
diff --git a/src/new.cpp b/src/new.cpp
index 9ad0612..964d87b 100644
--- a/src/new.cpp
+++ b/src/new.cpp
@@ -7,13 +7,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include <stdlib.h> 
-#include <cxxabi.h> 
+#include <stdlib.h>
 
 #include "new"
 
 
 #if __APPLE__
+    #include <cxxabi.h> 
     // On Darwin, there are two STL shared libraries and a lower level ABI
 	// shared libray.  The global holding the current new handler is
     // in the ABI library and named __cxa_new_handler.
diff --git a/src/stdexcept.cpp b/src/stdexcept.cpp
index e8960eb..5f3ffd7 100644
--- a/src/stdexcept.cpp
+++ b/src/stdexcept.cpp
@@ -15,7 +15,6 @@
 #include <cstdint>
 #include <cstddef>
 #include "system_error"
-#include <libkern/OSAtomic.h>
 
 // Note:  optimize for size
 
@@ -59,7 +58,7 @@
 __libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s)
     : str_(s.str_)
 {
-    OSAtomicIncrement32Barrier(&count());
+    __sync_add_and_fetch(&count(), 1);
 }
 
 __libcpp_nmstr&
@@ -67,8 +66,8 @@
 {
     const char* p = str_;
     str_ = s.str_;
-    OSAtomicIncrement32Barrier(&count());
-    if (OSAtomicDecrement32((count_t*)(p-sizeof(count_t))) < 0)
+    __sync_add_and_fetch(&count(), 1);
+    if (__sync_add_and_fetch((count_t*)(p-sizeof(count_t)), -1) < 0)
         delete [] (p-offset);
     return *this;
 }
@@ -76,7 +75,7 @@
 inline
 __libcpp_nmstr::~__libcpp_nmstr()
 {
-    if (OSAtomicDecrement32(&count()) < 0)
+    if (__sync_add_and_fetch(&count(), -1) < 0)
         delete [] (str_ - offset);
 }
 
diff --git a/src/system_error.cpp b/src/system_error.cpp
index 2e12aa8..3c1f000 100644
--- a/src/system_error.cpp
+++ b/src/system_error.cpp
@@ -64,9 +64,11 @@
 string
 __generic_error_category::message(int ev) const
 {
-    if (ev <= ELAST)
-        return __do_message::message(ev);
-    return string("unspecified generic_category error");
+#ifdef ELAST
+    if (ev > ELAST)
+      return string("unspecified generic_category error");
+#endif
+    return __do_message::message(ev);
 }
 
 const error_category&
@@ -94,17 +96,21 @@
 string
 __system_error_category::message(int ev) const
 {
-    if (ev <= ELAST)
-        return __do_message::message(ev);
-    return string("unspecified system_category error");
+#ifdef ELAST
+    if (ev > ELAST)
+      return string("unspecified system_category error");
+#endif
+    return __do_message::message(ev);
 }
 
 error_condition
 __system_error_category::default_error_condition(int ev) const
 {
-    if (ev <= ELAST)
-        return error_condition(ev, generic_category());
-    return error_condition(ev, system_category());
+#ifdef ELAST
+    if (ev > ELAST)
+      return error_condition(ev, system_category());
+#endif
+    return error_condition(ev, generic_category());
 }
 
 const error_category&
diff --git a/src/thread.cpp b/src/thread.cpp
index 4a7904d..2a6b205 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -15,7 +15,7 @@
 
 thread::~thread()
 {
-    if (__t_ != nullptr)
+    if (__t_ != 0)
         terminate();
 }
 
@@ -25,7 +25,7 @@
     int ec = pthread_join(__t_, 0);
     if (ec)
         throw system_error(error_code(ec, system_category()), "thread::join failed");
-    __t_ = nullptr;
+    __t_ = 0;
 }
 
 void
@@ -45,11 +45,17 @@
 unsigned
 thread::hardware_concurrency()
 {
+#if defined(CTL_HW) && defined(HW_NCPU)
     int n;
     int mib[2] = {CTL_HW, HW_NCPU};
     std::size_t s = sizeof(n);
     sysctl(mib, 2, &n, &s, 0, 0);
     return n;
+#else  // !defined(CTL_HW && HW_NCPU)
+    // TODO: grovel through /proc or check cpuid on x86 and similar
+    // instructions on other architectures.
+    return 0;  // Means not computable [thread.thread.static]
+#endif
 }
 
 namespace this_thread