diff --git a/src/OSspecific/POSIX/printStack.C b/src/OSspecific/POSIX/printStack.C
index e9310dfb7e..eb98c5338f 100644
--- a/src/OSspecific/POSIX/printStack.C
+++ b/src/OSspecific/POSIX/printStack.C
@@ -115,7 +115,13 @@ void printSourceFileAndLine
     uintptr_t address = uintptr_t(addr);
     word myAddress = addressToWord(address);
 
-    if (filename.ext() == "so")
+    if
+    (
+        filename.hasExt("so")
+        #ifdef darwin
+     || filename.hasExt("dylib")
+        #endif
+    )
     {
         // Convert address into offset into dynamic library
         uintptr_t offset = uintptr_t(info->dli_fbase);
diff --git a/src/OSspecific/POSIX/signals/feexceptErsatz.H b/src/OSspecific/POSIX/signals/feexceptErsatz.H
new file mode 100644
index 0000000000..1b866242f2
--- /dev/null
+++ b/src/OSspecific/POSIX/signals/feexceptErsatz.H
@@ -0,0 +1,74 @@
+// ============================================================================
+// Generic handling of floating point exceptions
+//
+// 2018 Alexey Matveichev
+// ----------------------------------------------------------------------------
+//
+// Original Author
+//     David N. Williams
+//
+// License
+//     Public Domain
+//
+// Description
+//     Alternate, nondefault handling of IEEE 754 floating-point exceptions
+//     in OS X, based on the GNU functions feenableexcept(), fedisableeexcept()
+//     and fegetexcept() [in libm]
+//
+// http://www-personal.umich.edu/~williams/archive/computation/fe-handling-example.c
+// ============================================================================
+
+#ifndef feexceptErsatz_H
+#define feexceptErsatz_H
+#ifdef darwin
+
+#include <fenv.h>
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+inline int feenableexcept(unsigned int excepts)
+{
+    static fenv_t fenv;
+    unsigned int new_excepts = excepts & FE_ALL_EXCEPT;
+    unsigned int old_excepts;   // previous masks
+
+    if (fegetenv(&fenv))
+    {
+        return -1;
+    }
+    old_excepts = fenv.__control & FE_ALL_EXCEPT;
+
+    // unmask
+    fenv.__control &= ~new_excepts;
+    fenv.__mxcsr   &= ~(new_excepts << 7);
+
+    return fesetenv(&fenv) ? -1 : old_excepts;
+}
+
+
+inline int fedisableexcept(unsigned int excepts)
+{
+    static fenv_t fenv;
+    unsigned int new_excepts = excepts & FE_ALL_EXCEPT;
+    unsigned int old_excepts;   // all previous masks
+
+    if (fegetenv(&fenv))
+    {
+        return -1;
+    }
+
+    old_excepts = fenv.__control & FE_ALL_EXCEPT;
+
+    // mask
+    fenv.__control |= new_excepts;
+    fenv.__mxcsr   |= new_excepts << 7;
+
+    return fesetenv(&fenv) ? -1 : old_excepts;
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif  // darwin
+#endif
+
+// ************************************************************************* //
diff --git a/src/OSspecific/POSIX/signals/sigFpe.C b/src/OSspecific/POSIX/signals/sigFpe.C
index 1fd6f03b24..5862efa061 100644
--- a/src/OSspecific/POSIX/signals/sigFpe.C
+++ b/src/OSspecific/POSIX/signals/sigFpe.C
@@ -41,6 +41,10 @@ License
     #include <sigfpe.h>
 #endif
 
+#ifdef darwin
+    #include "feexceptErsatz.H"
+#endif
+
 #include <limits>
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
@@ -108,11 +112,15 @@ void* Foam::sigFpe::mallocNan(size_t size)
 
     return result;
 }
+#endif  // __linux__
 
 
-#ifdef __GNUC__
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
 void Foam::sigFpe::sigHandler(int)
 {
+    #if (defined(__linux__) && defined(__GNUC__)) || defined(darwin)
+
     // Reset old handling
     if (sigaction(SIGFPE, &oldAction_, nullptr) < 0)
     {
@@ -124,9 +132,9 @@ void Foam::sigFpe::sigHandler(int)
     jobInfo.signalEnd();        // Update jobInfo file
     error::printStack(Perr);
     raise(SIGFPE);              // Throw signal (to old handler)
+
+    #endif  // (__linux__ && __GNUC__) || darwin
 }
-#endif  // __GNUC__
-#endif  // __linux__
 
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
@@ -157,7 +165,7 @@ void Foam::sigFpe::set(bool verbose)
 {
     if (!sigActive_ && requested())
     {
-        #if defined(__linux__) && defined(__GNUC__)
+        #if (defined(__linux__) && defined(__GNUC__)) || defined(darwin)
 
         feenableexcept
         (
@@ -247,7 +255,7 @@ void Foam::sigFpe::set(bool verbose)
 
 void Foam::sigFpe::unset(bool verbose)
 {
-    #if defined(__linux__) && defined(__GNUC__)
+    #if (defined(__linux__) && defined(__GNUC__)) || defined(darwin)
     if (sigActive_)
     {
         if (verbose)
diff --git a/src/OSspecific/POSIX/signals/sigFpe.H b/src/OSspecific/POSIX/signals/sigFpe.H
index c8301c72c8..1e9d21aadb 100644
--- a/src/OSspecific/POSIX/signals/sigFpe.H
+++ b/src/OSspecific/POSIX/signals/sigFpe.H
@@ -91,12 +91,10 @@ class sigFpe
         static struct sigaction oldAction_;
 
 
-    // Static data members
+    // Private Member Functions
 
-        #if defined(__linux__) && defined(__GNUC__)
         //- Handler for caught signals
         static void sigHandler(int);
-        #endif
 
 
 public:
@@ -111,7 +109,7 @@ public:
     ~sigFpe();
 
 
-    // Member functions
+    // Member Functions
 
         //- Check if SIGFPE signals handler is to be enabled.
         //  This is controlled by the trapFpe entry or the FOAM_SIGFPE
diff --git a/src/OSspecific/POSIX/signals/sigStopAtWriteNow.H b/src/OSspecific/POSIX/signals/sigStopAtWriteNow.H
index beed3d37b8..f26ff03aa6 100644
--- a/src/OSspecific/POSIX/signals/sigStopAtWriteNow.H
+++ b/src/OSspecific/POSIX/signals/sigStopAtWriteNow.H
@@ -73,7 +73,7 @@ class sigStopAtWriteNow
 
 public:
 
-    //- wip. Have setter have access to signal_
+    //- Allow setter access to signal_
     friend class addstopAtWriteNowSignalToOpt;
 
 
diff --git a/src/OSspecific/POSIX/signals/sigWriteNow.H b/src/OSspecific/POSIX/signals/sigWriteNow.H
index 6190bd99ba..2ac02f9638 100644
--- a/src/OSspecific/POSIX/signals/sigWriteNow.H
+++ b/src/OSspecific/POSIX/signals/sigWriteNow.H
@@ -74,9 +74,10 @@ public:
 
     friend class sigStopAtWriteNow;
 
-    //- wip. Have setter have access to signal_
+    //- Allow setter access to signal_
     friend class addwriteNowSignalToOpt;
 
+
     // Constructors
 
         //- Construct null
@@ -90,7 +91,7 @@ public:
     ~sigWriteNow();
 
 
-    // Member functions
+    // Member Functions
 
         //- Is active?
         bool active() const;
diff --git a/wmake/rules/darwin64Clang/CGAL b/wmake/rules/darwin64Clang/CGAL
new file mode 100644
index 0000000000..ced2de6c90
--- /dev/null
+++ b/wmake/rules/darwin64Clang/CGAL
@@ -0,0 +1,10 @@
+# Clang build of CGAL on Darwin without mpfr,gmp
+
+CGAL_INC = \
+    -I$(BOOST_ARCH_PATH)/include \
+    -I$(CGAL_ARCH_PATH)/include
+
+CGAL_LIBS = \
+    -L$(BOOST_ARCH_PATH)/lib \
+    -L$(CGAL_ARCH_PATH)/lib \
+    -lCGAL