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
     {