Windows compiles! (w/Visual Studio 2012) That's about all it does, but it's a start.

node/Logger.cpp

@@ -30,6 +30,8 @@
 #include <string.h>
 #include <stdarg.h>
 #include <time.h>
+
+#include "Constants.hpp"
 #include "Logger.hpp"
 
 namespace ZeroTier {
@@ -64,7 +66,12 @@ void Logger::log(const char *fmt,...)
 
 		if (_log) {
 			time_t now = time(0);
+#ifdef __WINDOWS__
+			ctime_s(tmp,sizeof(tmp),&now);
+			char *nowstr = tmp;
+#else
 			char *nowstr = ctime_r(&now,tmp);
+#endif
 			for(char *c=nowstr;*c;++c) {
 				if (*c == '\n')
 					*c = '\0';