diff --git a/CMakeLists.txt b/CMakeLists.txt
index 864c3aabd5..19c4b900b6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,9 +16,10 @@ add_definitions (
   -D__STDC_CONSTANT_MACROS
 )
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Werror -fno-exceptions -std=c++0x")
-
 include ("cmake/Platform.cmake")
+
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${PLATFORM_CXX_FLAGS}")
+
 include (CTest)
 
 # Sadly, we can't use the 'test' target, as that's coopted by ctest
diff --git a/cmake/Platform.cmake b/cmake/Platform.cmake
index 85470acdeb..1bfb373ee7 100644
--- a/cmake/Platform.cmake
+++ b/cmake/Platform.cmake
@@ -6,3 +6,10 @@ IF (APPLE)
 
    SET(PLATFORM_LIBS ${CORE_FOUNDATION_LIBRARY})
 ENDIF()
+
+IF (MSVC)
+	SET(PLATFORM_CXX_FLAGS "/Wall")
+ELSE()
+	SET(PLATFORM_CXX_FLAGS "-Wall -Werror -fno-exceptions -std=c++0x")
+  SET(PLATFORM_LIBS ${PLATFORM_LIBS} pthread dl)
+ENDIF()
diff --git a/include/avian/codegen/compiler.h b/include/avian/codegen/compiler.h
index 9e96e79539..5086367cd4 100644
--- a/include/avian/codegen/compiler.h
+++ b/include/avian/codegen/compiler.h
@@ -32,8 +32,13 @@ class Args {
 
   template <class... Ts>
   Args(Ts... ts)
+#ifndef _MSC_VER
       : values{ts...}
+#endif
   {
+#ifdef _MSC_VER
+    setArrayElements(values, ts...);
+#endif
   }
 
   operator util::Slice<ir::Value*>()
diff --git a/include/avian/util/cpp.h b/include/avian/util/cpp.h
index 6be12af1a8..209df50a46 100644
--- a/include/avian/util/cpp.h
+++ b/include/avian/util/cpp.h
@@ -44,6 +44,16 @@ struct ArgumentCount<> {
   enum { Result = 0 };
 };
 
+template<class T>
+void setArrayElements(T*) {
+}
+
+template<class T, class... Ts>
+void setArrayElements(T* arr, T elem, Ts... ts) {
+  *arr = elem;
+  setArrayElements(arr, ts...);
+}
+
 }  // namespace util
 }  // namespace avian
 
diff --git a/src/avian/common.h b/src/avian/common.h
index 82cdc046ce..b08e2dc659 100644
--- a/src/avian/common.h
+++ b/src/avian/common.h
@@ -39,29 +39,9 @@
 
 #define strncasecmp _strnicmp
 
-#define FP_NAN 0
-#define FP_INFINITE 1
 #define FP_UNDEF 2
 
-inline int fpclassify(double d)
-{
-  switch (_fpclass(d)) {
-  case _FPCLASS_SNAN:
-  case _FPCLASS_QNAN:
-    return FP_NAN;
-  case _FPCLASS_PINF:
-  case _FPCLASS_NINF:
-    return FP_INFINITE;
-  }
-  return FP_UNDEF;
-}
-
-inline int signbit(double d)
-{
-  return _copysign(1.0, d) < 0;
-}
-
-#define not!
+#define not !
 #define or ||
 #define and &&
 #define xor ^
diff --git a/src/system/CMakeLists.txt b/src/system/CMakeLists.txt
index 566ac8100f..5c6f2a58fa 100644
--- a/src/system/CMakeLists.txt
+++ b/src/system/CMakeLists.txt
@@ -1,3 +1,7 @@
 
-# TODO: use posix.cpp or windows.cpp, depending on platform
-add_library(avian_system posix.cpp posix/crash.cpp)
+if (MSVC)
+  #todo: support mingw compiler
+  add_library(avian_system windows.cpp windows/crash.cpp)
+else()
+  add_library(avian_system posix.cpp posix/crash.cpp)
+endif()
diff --git a/src/tools/binary-to-object/main.cpp b/src/tools/binary-to-object/main.cpp
index 4cd9ff5879..8889dbaf24 100644
--- a/src/tools/binary-to-object/main.cpp
+++ b/src/tools/binary-to-object/main.cpp
@@ -16,6 +16,7 @@
 #include <sys/stat.h>
 #ifdef WIN32
 #include <windows.h>
+#include <io.h>
 #else
 #include <sys/mman.h>
 #include <unistd.h>
@@ -90,7 +91,7 @@ void usageAndExit(const char* name)
 
 int main(int argc, const char** argv)
 {
-  if (argc < 7 or argc > 10) {
+  if (argc < 7 || argc > 10) {
     usageAndExit(argv[0]);
   }
 
diff --git a/src/tools/object-writer/pe.cpp b/src/tools/object-writer/pe.cpp
index dd3e976041..8384cbd64a 100644
--- a/src/tools/object-writer/pe.cpp
+++ b/src/tools/object-writer/pe.cpp
@@ -40,6 +40,12 @@ namespace {
 #define IMAGE_SCN_MEM_WRITE 0x80000000
 #define IMAGE_SCN_CNT_CODE 32
 
+#ifdef _MSC_VER
+#define PACKED_STRUCT _declspec(align(1))
+#else
+#define PACKED_STRUCT __attribute__((packed))
+#endif
+
 struct IMAGE_FILE_HEADER {
   uint16_t Machine;
   uint16_t NumberOfSections;
@@ -48,7 +54,7 @@ struct IMAGE_FILE_HEADER {
   uint32_t NumberOfSymbols;
   uint16_t SizeOfOptionalHeader;
   uint16_t Characteristics;
-} __attribute__((packed));
+} PACKED_STRUCT;
 
 struct IMAGE_SECTION_HEADER {
   uint8_t Name[IMAGE_SIZEOF_SHORT_NAME];
@@ -64,7 +70,7 @@ struct IMAGE_SECTION_HEADER {
   uint16_t NumberOfRelocations;
   uint16_t NumberOfLinenumbers;
   uint32_t Characteristics;
-} __attribute__((packed));
+} PACKED_STRUCT;
 
 struct IMAGE_SYMBOL {
   union {
@@ -78,7 +84,7 @@ struct IMAGE_SYMBOL {
   uint16_t Type;
   uint8_t StorageClass;
   uint8_t NumberOfAuxSymbols;
-} __attribute__((packed));
+} PACKED_STRUCT;
 // --- winnt.h ----
 
 inline unsigned pad(unsigned n)
diff --git a/src/tools/object-writer/tools.cpp b/src/tools/object-writer/tools.cpp
index 5bd3739825..ad736efd24 100644
--- a/src/tools/object-writer/tools.cpp
+++ b/src/tools/object-writer/tools.cpp
@@ -94,13 +94,13 @@ Platform* Platform::first = 0;
 
 PlatformInfo::Format PlatformInfo::formatFromString(const char* format)
 {
-  if (strcmp(format, "elf") == 0 or strcmp(format, "linux") == 0
-      or strcmp(format, "freebsd") == 0 or strcmp(format, "qnx") == 0) {
+  if (strcmp(format, "elf") == 0 || strcmp(format, "linux") == 0
+      || strcmp(format, "freebsd") == 0 || strcmp(format, "qnx") == 0) {
     return Elf;
-  } else if (strcmp(format, "pe") == 0 or strcmp(format, "windows") == 0) {
+  } else if (strcmp(format, "pe") == 0 || strcmp(format, "windows") == 0) {
     return Pe;
-  } else if (strcmp(format, "macho") == 0 or strcmp(format, "darwin") == 0
-             or strcmp(format, "ios") == 0 or strcmp(format, "macosx") == 0) {
+  } else if (strcmp(format, "macho") == 0 || strcmp(format, "darwin") == 0
+             || strcmp(format, "ios") == 0 || strcmp(format, "macosx") == 0) {
     return MachO;
   } else {
     return UnknownFormat;
@@ -110,13 +110,13 @@ PlatformInfo::Format PlatformInfo::formatFromString(const char* format)
 PlatformInfo::Architecture PlatformInfo::archFromString(const char* arch)
 {
   if (strcmp(arch, "i386") == 0) {
-    return x86;
+    return Architecture::x86;
   } else if (strcmp(arch, "x86_64") == 0) {
-    return x86_64;
+    return Architecture::x86_64;
   } else if (strcmp(arch, "arm") == 0) {
-    return Arm;
+    return Architecture::Arm;
   } else {
-    return UnknownArch;
+    return Architecture::UnknownArch;
   }
 }
 
diff --git a/src/tools/type-generator/io.h b/src/tools/type-generator/io.h
index 346ca5fa84..f0ae32135f 100644
--- a/src/tools/type-generator/io.h
+++ b/src/tools/type-generator/io.h
@@ -124,7 +124,7 @@ class Output {
   {
     static const int Size = 32;
     char s[Size];
-    int c UNUSED = ::snprintf(s, Size, "%d", i);
+    int c UNUSED = vm::snprintf(s, Size, "%d", i);
     assert(c > 0 and c < Size);
     write(s);
   }
diff --git a/src/tools/type-generator/main.cpp b/src/tools/type-generator/main.cpp
index 30549afd43..32dcf6f7f0 100644
--- a/src/tools/type-generator/main.cpp
+++ b/src/tools/type-generator/main.cpp
@@ -172,7 +172,7 @@ class Class {
     return ss.str();
   }
 
-  void dumpToStdout() const AVIAN_EXPORT
+  void dumpToStdout() const
   {
     printf("%s\n", dump().c_str());
   }
@@ -615,13 +615,14 @@ const char* fieldType(const char* spec)
 
 void parseJavaClass(Module& module, ClassParser& clparser, Stream* s)
 {
-  uint32_t magic UNUSED = s->read4();
+  uint32_t magic = s->read4();
   assert(magic == 0xCAFEBABE);
+  (void)magic;
   s->read2();  // minor version
   s->read2();  // major version
 
   unsigned poolCount = s->read2() - 1;
-  uintptr_t pool[poolCount];
+  std::vector<uintptr_t> pool(poolCount, -1);
   for (unsigned i = 0; i < poolCount; ++i) {
     unsigned c = s->read1();
 
diff --git a/unittest/CMakeLists.txt b/unittest/CMakeLists.txt
index 0f4520d162..d810e3ffba 100644
--- a/unittest/CMakeLists.txt
+++ b/unittest/CMakeLists.txt
@@ -16,8 +16,6 @@ target_link_libraries (avian_unittest
   avian_system
   avian_heap
   avian_util
-  pthread
-  dl
   ${PLATFORM_LIBS}
 )