diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0c29e52e..39c8aadd 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -91,3 +91,21 @@ jobs:
     - name: Build dedicated linux-amd64
       run: |
         scripts/build-ubuntu-amd64.sh -d
+
+  build-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build macos-amd64
+      run: |
+        scripts/build-macos-amd64.sh
+
+  build-dedicated-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build dedicated macos-amd64
+      run: |
+        scripts/build-macos-amd64.sh -d
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c21d0a55..d8adc5ab 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -21,6 +21,15 @@ jobs:
       run: |
         scripts/tests-ubuntu-amd64.sh
 
+  tests-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run tests macos-amd64
+      run: |
+        scripts/tests-macos-amd64.sh
+
   tests-windows-i386:
     runs-on: windows-2019
 
diff --git a/appframework/sdlmgr.cpp b/appframework/sdlmgr.cpp
index bad06f1b..dd5ee2c2 100644
--- a/appframework/sdlmgr.cpp
+++ b/appframework/sdlmgr.cpp
@@ -2224,7 +2224,7 @@ GLMDisplayDB *CSDLMgr::GetDisplayDB( void )
 }
 
 #ifndef OSX
-# include "glmdisplaydb_linuxwin.inl"
+#include "glmdisplaydb_linuxwin.inl"
 #endif
 
 
diff --git a/appframework/wscript b/appframework/wscript
index 0fea261a..f8ded318 100755
--- a/appframework/wscript
+++ b/appframework/wscript
@@ -24,11 +24,10 @@ def build(bld):
 		source += [
 			'sdlmgr.cpp'
 		]
-	
-	if bld.env.DEST_OS == 'darwin':
-		source += [
-			'glmrendererinfo_osx.mm'
-		]
+
+	if bld.env.DEST_OS == 'darwin' and bld.env.GL:
+		source += ['glmrendererinfo_osx.mm']
+
 
 	if bld.env.DEST_OS == 'win32':
 		source += [
diff --git a/bitmap/ImageByteSwap.cpp b/bitmap/ImageByteSwap.cpp
index 57217f15..44fc5fa6 100644
--- a/bitmap/ImageByteSwap.cpp
+++ b/bitmap/ImageByteSwap.cpp
@@ -88,14 +88,7 @@ namespace ImageLoader
 
 		Assert( IsFormatValidForConversion( imageFormat ) );
 
-#if !defined( DX_TO_GL_ABSTRACTION ) && !defined( NO_X360_XDK )
-		if ( IsPC() )
-		{
-			// running as a win32 tool, data is in expected order
-			// for conversion code
-			return;
-		}
-
+#ifdef _X360
 		// running on 360 and converting, input data must be x86 order
 		// swap to ensure conversion code gets valid data
 		XGENDIANTYPE xEndian;
@@ -137,7 +130,7 @@ namespace ImageLoader
 	{
 		Assert( IsFormatValidForConversion( imageFormat ) );
 
-#if !defined( DX_TO_GL_ABSTRACTION ) && !defined( NO_X360_XDK )
+#ifdef _X360
 		// It would have been nice to use the 360 D3DFORMAT bit encodings, but the codes
 		// are different for win32, and this routine is used by a win32 library to
 		// manipulate 360 data, so there can be no reliance on D3DFORMAT bits
@@ -201,7 +194,7 @@ namespace ImageLoader
 	{
 		Assert( IsFormatValidForConversion( imageFormat ) );
 
-#if !defined( DX_TO_GL_ABSTRACTION ) && !defined( NO_X360_XDK )
+#ifdef _X360
 		XGENDIANTYPE xEndian;
 		switch ( imageFormat )
 		{
@@ -256,5 +249,4 @@ namespace ImageLoader
 		}
 #endif
 	}
-	
 }
diff --git a/bitmap/imageformat.cpp b/bitmap/imageformat.cpp
index c2222653..6e2c99c1 100644
--- a/bitmap/imageformat.cpp
+++ b/bitmap/imageformat.cpp
@@ -288,13 +288,11 @@ int GetNumMipMapLevels( int width, int height, int depth )
 // Turn off warning about FOURCC formats below...
 #pragma warning (disable:4063)
 
-#ifdef DX_TO_GL_ABSTRACTION
 #ifndef MAKEFOURCC
 #define MAKEFOURCC(ch0, ch1, ch2, ch3)                              \
 	((DWORD)(BYTE)(ch0) | ((DWORD)(BYTE)(ch1) << 8) |   \
 	((DWORD)(BYTE)(ch2) << 16) | ((DWORD)(BYTE)(ch3) << 24 ))
 #endif //defined(MAKEFOURCC)
-#endif	
 //-----------------------------------------------------------------------------
 // convert back and forth from D3D format to ImageFormat, regardless of
 // whether it's supported or not
diff --git a/filesystem/filesystem_async.cpp b/filesystem/filesystem_async.cpp
index 769ed017..493b1b70 100644
--- a/filesystem/filesystem_async.cpp
+++ b/filesystem/filesystem_async.cpp
@@ -659,8 +659,9 @@ void CBaseFileSystem::InitAsync()
 		Msg( "Async I/O disabled from command line\n" );
 		return;
 	}
-
+#ifndef UNITTESTS
 	if ( VCRGetMode() == VCR_Disabled )
+#endif
 	{
 		// create the i/o thread pool
 		m_pThreadPool = CreateThreadPool();
@@ -668,7 +669,6 @@ void CBaseFileSystem::InitAsync()
 		ThreadPoolStartParams_t params;
 		params.iThreadPriority = 0;
 		params.bIOThreads = true;
-		params.nThreadsMax = 4; // Limit count of IO threads to a maximum of 4.
 		if ( IsX360() )
 		{
 			// override defaults
@@ -678,11 +678,10 @@ void CBaseFileSystem::InitAsync()
 			params.bUseAffinityTable = true;
 			params.iAffinityTable[0] = XBOX_PROCESSOR_3;
 		}
-		else if( IsPC() )
+		else
 		{
-			// override defaults
-			// maximum # of async I/O thread on PC is 2
-			params.nThreads = 1;
+			params.nThreadsMax = MIN(params.nThreads, 4); // Limit count of IO threads to a maximum of 4.
+			params.nStackSize = 256*1024;
 		}
 
 		if ( !m_pThreadPool->Start( params, "IOJob" ) )
diff --git a/scripts/build-macos-amd64.sh b/scripts/build-macos-amd64.sh
new file mode 100755
index 00000000..de0e8cfd
--- /dev/null
+++ b/scripts/build-macos-amd64.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+git submodule init && git submodule update
+
+brew install sdl2
+
+./waf configure -T debug --64bits --disable-warns $* &&
+./waf build
diff --git a/scripts/tests-macos-amd64.sh b/scripts/tests-macos-amd64.sh
new file mode 100755
index 00000000..ff4e46b2
--- /dev/null
+++ b/scripts/tests-macos-amd64.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+git submodule init && git submodule update
+./waf configure -T release --sanitize=address,undefined --disable-warns --tests -8 --prefix=out/ $* &&
+./waf install &&
+cd out &&
+DYLD_LIBRARY_PATH=bin/ ./unittest || exit 1
diff --git a/tier2/renderutils.cpp b/tier2/renderutils.cpp
index 9b35e9fb..1c4870d8 100644
--- a/tier2/renderutils.cpp
+++ b/tier2/renderutils.cpp
@@ -12,7 +12,7 @@
 #include "materialsystem/imaterial.h"
 #include "tier0/vprof.h"
 #include "tier0/basetypes.h"
-#ifndef DEDICATED
+#ifdef DX_TO_GL_ABSTRACTION
 #include "togl/rendermechanism.h"
 #endif
 
diff --git a/utils/unittest/unittest.cpp b/utils/unittest/unittest.cpp
index 9135c67c..898e86e7 100644
--- a/utils/unittest/unittest.cpp
+++ b/utils/unittest/unittest.cpp
@@ -128,7 +128,7 @@ bool CUnitTestApp::Create()
 		while ((dir = readdir(d)) != NULL)
 		{
 			int len = strlen(dir->d_name);
-			if( len > 2 && strcmp(dir->d_name+len-3, ".so") == 0)
+			if( len > 2 && strcmp(dir->d_name+len-strlen(DLL_EXT_STRING), DLL_EXT_STRING) == 0)
 			{
 				static char path[2048];
 				snprintf(path, sizeof(path), "tests/%s", dir->d_name);
diff --git a/wscript b/wscript
index 7441473c..ada484c5 100644
--- a/wscript
+++ b/wscript
@@ -159,15 +159,17 @@ def define_platform(conf):
 	conf.env.DEDICATED = conf.options.DEDICATED
 	conf.env.TESTS = conf.options.TESTS
 	conf.env.TOGLES = conf.options.TOGLES
-	conf.env.GL = conf.options.GL
+	conf.env.GL = conf.options.GL and not conf.options.TESTS and not conf.options.DEDICATED
 	conf.env.OPUS = conf.options.OPUS
 
 	if conf.options.DEDICATED:
 		conf.options.SDL = False
-#		conf.options.GL = False
 		conf.define('DEDICATED', 1)
 
-	if conf.options.GL and not conf.options.TESTS:
+	if conf.options.TESTS:
+		conf.define('UNITTESTS', 1)
+
+	if conf.env.GL:
 		conf.env.append_unique('DEFINES', [
 			'DX_TO_GL_ABSTRACTION',
 			'GL_GLEXT_PROTOTYPES',
@@ -177,6 +179,9 @@ def define_platform(conf):
 	if conf.options.TOGLES:
 		conf.env.append_unique('DEFINES', ['TOGLES'])
 
+	if conf.options.TESTS:
+		conf.define('UNITTESTS', 1)
+
 	if conf.options.SDL and not conf.options.TESTS:
 		conf.env.SDL = 1
 		conf.define('USE_SDL', 1)
@@ -323,6 +328,20 @@ def check_deps(conf):
 			for i in a:
 				conf.check_cc(lib = i)
 
+	if conf.env.DEST_OS == "darwin":
+		conf.check(lib='iconv', uselib_store='ICONV')
+		conf.env.FRAMEWORK_APPKIT = "AppKit"
+		conf.env.FRAMEWORK_IOKIT = "IOKit"
+		conf.env.FRAMEWORK_FOUNDATION = "Foundation"
+		conf.env.FRAMEWORK_COREFOUNDATION = "CoreFoundation"
+		conf.env.FRAMEWORK_COREGRAPHICS = "CoreGraphics"
+		conf.env.FRAMEWORK_OPENGL = "OpenGL"
+		conf.env.FRAMEWORK_CARBON = "Carbon"
+		conf.env.FRAMEWORK_APPLICATIONSERVICES = "ApplicationServices"
+		conf.env.FRAMEWORK_CORESERVICES = "CoreServices"
+		conf.env.FRAMEWORK_COREAUDIO = "CoreAudio"
+		conf.env.FRAMEWORK_AUDIOTOOLBOX = "AudioToolbox"
+		conf.env.FRAMEWORK_SYSTEMCONFIGURATION = "SystemConfiguration"
 
 	if conf.options.TESTS:
 		return
@@ -361,21 +380,6 @@ def check_deps(conf):
 		conf.check(lib='android_support', uselib_store='ANDROID_SUPPORT')
 		conf.check(lib='opus', uselib_store='OPUS')
 
-	if conf.env.DEST_OS == "darwin":
-		conf.check(lib='iconv', uselib_store='ICONV')
-		conf.env.FRAMEWORK_APPKIT = "AppKit"
-		conf.env.FRAMEWORK_IOKIT = "IOKit"
-		conf.env.FRAMEWORK_FOUNDATION = "Foundation"
-		conf.env.FRAMEWORK_COREFOUNDATION = "CoreFoundation"
-		conf.env.FRAMEWORK_COREGRAPHICS = "CoreGraphics"
-		conf.env.FRAMEWORK_OPENGL = "OpenGL"
-		conf.env.FRAMEWORK_CARBON = "Carbon"
-		conf.env.FRAMEWORK_APPLICATIONSERVICES = "ApplicationServices"
-		conf.env.FRAMEWORK_CORESERVICES = "CoreServices"
-		conf.env.FRAMEWORK_COREAUDIO = "CoreAudio"
-		conf.env.FRAMEWORK_AUDIOTOOLBOX = "AudioToolbox"
-		conf.env.FRAMEWORK_SYSTEMCONFIGURATION = "SystemConfiguration"
-
 	if conf.env.DEST_OS == 'win32':
 		conf.check(lib='libz', uselib_store='ZLIB', define_name='USE_ZLIB')
 		# conf.check(lib='nvtc', uselib_store='NVTC')