diff --git a/lib/mac/mathlib_i486.a b/lib/mac/mathlib_i486.a
index 17f5246e..be75fd9f 100644
Binary files a/lib/mac/mathlib_i486.a and b/lib/mac/mathlib_i486.a differ
diff --git a/lib/mac/tier1_i486.a b/lib/mac/tier1_i486.a
index 11c297c4..d4ba40aa 100644
Binary files a/lib/mac/tier1_i486.a and b/lib/mac/tier1_i486.a differ
diff --git a/linux_sdk/Makefile b/linux_sdk/Makefile
index 9963177a..dd3dd73b 100644
--- a/linux_sdk/Makefile
+++ b/linux_sdk/Makefile
@@ -3,6 +3,8 @@
 #
 #
 
+OS := $(shell uname -s)
+
 #############################################################################
 # Developer configurable items
 #############################################################################
@@ -24,10 +26,17 @@ SRCDS_DIR = ~/srcds/orangebox
 GAME_DIR = $(SRCDS_DIR)/scratchmod
 
 # compiler options (gcc 3.4.1 or above is required - 4.1.2+ recommended)
-CC = /usr/bin/gcc-4.2
-CPLUS = /usr/bin/g++-4.2
-CLINK = /usr/bin/gcc-4.2
-CPP_LIB = "libstdc++.a libgcc_eh.a"
+ifeq "$(OS)" "Darwin"
+CC = /usr/bin/clang
+CPLUS = /usr/bin/clang++
+CLINK = /usr/bin/clang
+CPP_LIB =
+else
+CC = /usr/bin/gcc
+CPLUS = /usr/bin/g++
+CLINK = /usr/bin/gcc
+CPP_LIB = $(SRCDS_DIR)/bin/libstdc++.so.6 $(SRCDS_DIR)/bin/libgcc_s.so.1
+endif
 
 # put any compiler flags you want passed here
 USER_CFLAGS =
@@ -58,21 +67,37 @@ BUILD_OBJ_DIR = $(BUILD_DIR)/obj
 
 # the location of the source code
 SRC_DIR = ..
-# the location of the Linux static libraries
+
+# the location of the static libraries
+ifeq "$(OS)" "Darwin"
+LIB_DIR = $(SRC_DIR)/lib/mac
+else
 LIB_DIR = $(SRC_DIR)/lib/linux
+endif
 
 # the CPU target for the build, must be i486 for now
 ARCH = i486
 ARCH_CFLAGS = -mtune=i686 -march=pentium3 -mmmx -m32
 
-DEFINES = -D_LINUX -DLINUX -DVPROF_LEVEL=1 -DSWDS -D_finite=finite -Dstricmp=strcasecmp -D_stricmp=strcasecmp \
-	-D_strnicmp=strncasecmp -Dstrnicmp=strncasecmp -D_vsnprintf=vsnprintf -D_alloca=alloca -Dstrcmpi=strcasecmp
+ifeq "$(OS)" "Darwin"
+DEFINES = -D_OSX -DOSX
+SHLIBEXT = dylib
+SHLIBLDFLAGS = -dynamiclib -mmacosx-version-min=10.5
+SHLIBSUFFIX = 
+else
+DEFINES = -D_LINUX -DLINUX
+SHLIBEXT = so
+SHLIBLDFLAGS = -shared -Wl,-Map,$@_map.txt -Wl
+SHLIBSUFFIX = 
+endif
+
+DEFINES +=-DVPROF_LEVEL=1 -DSWDS -D_finite=finite -Dstricmp=strcasecmp -D_stricmp=strcasecmp -D_strnicmp=strncasecmp \
+	-Dstrnicmp=strncasecmp -D_vsnprintf=vsnprintf -D_alloca=alloca -Dstrcmpi=strcasecmp
 UNDEF = -Usprintf -Ustrncpy -UPROTECTED_THINGS_ENABLE
 
-BASE_CFLAGS = -fno-strict-aliasing -Wall -Werror -Wconversion -Wno-non-virtual-dtor -Wno-invalid-offsetof
-SHLIBEXT = so
+BASE_CFLAGS = -fno-strict-aliasing -Wall -Wsign-compare -Werror -Wno-conversion -Wno-overloaded-virtual -Wno-non-virtual-dtor -Wno-invalid-offsetof \
+	      -Wno-delete-non-virtual-dtor
 SHLIBCFLAGS = -fPIC
-SHLIBLDFLAGS = -shared -Wl,-Map,$@_map.txt -Wl
 
 # Flags passed to the c compiler
 CFLAGS = $(DEFINES) $(ARCH_CFLAGS) -O3 $(BASE_CFLAGS)
@@ -88,7 +113,7 @@ DBG_CFLAGS = "$(DEFINES) $(ARCH_CFLAGS) -g -ggdb $(BASE_CFLAGS) $(UNDEF)"
 # define list passed to make for the sub makefile
 BASE_DEFINES = CC=$(CC) AR=$(AR) CPLUS=$(CPLUS) CPP_LIB=$(CPP_LIB) DEBUG=$(DEBUG) \
 	BUILD_DIR=$(BUILD_DIR) BUILD_OBJ_DIR=$(BUILD_OBJ_DIR) SRC_DIR=$(SRC_DIR) \
-	LIB_DIR=$(LIB_DIR) SHLIBLDFLAGS=$(SHLIBLDFLAGS) SHLIBEXT=$(SHLIBEXT) \
+	LIB_DIR=$(LIB_DIR) SHLIBLDFLAGS="$(SHLIBLDFLAGS)" SHLIBEXT=$(SHLIBEXT) SHLIBSUFFIX=$(SHLIBSUFFIX) \
 	CLINK=$(CLINK) CFLAGS="$(CFLAGS)" DBG_CFLAGS=$(DBG_CFLAGS) LDFLAGS=$(LDFLAGS) \
 	DEFINES="$(DEFINES)" DBG_DEFINES=$(DBG_DEFINES) \
 	ARCH=$(ARCH) SRCDS_DIR=$(SRCDS_DIR) MOD_CONFIG=$(MOD_CONFIG) NAME=$(NAME) \
@@ -111,9 +136,9 @@ check:
 	if [ ! -e "$(LIB_DIR)/tier1_i486.a" ]; then $(MAKE) tier1;fi
 	if [ ! -e "$(LIB_DIR)/mathlib_i486.a" ]; then $(MAKE) mathlib;fi
 	if [ ! -e "$(LIB_DIR)/choreoobjects_i486.a" ]; then $(MAKE) choreo;fi
-	if [ ! -f "tier0_i486.so" ]; then ln -s $(SRCDS_DIR)/bin/tier0_i486.so .; fi
-	if [ ! -f "vstdlib_i486.so" ]; then ln -s $(SRCDS_DIR)/bin/vstdlib_i486.so .; fi
-	if [ ! -f "steam_api_i486.so" ]; then ln -s $(SRCDS_DIR)/bin/steam_api_i486.so .; fi
+	if [ ! -f "libtier0$(SHLIBSUFFIX).$(SHLIBEXT)" ]; then ln -fs $(LIB_DIR)/libtier0$(SHLIBSUFFIX).$(SHLIBEXT) .; fi
+	if [ ! -f "libvstdlib$(SHLIBSUFFIX).$(SHLIBEXT)" ]; then ln -fs $(LIB_DIR)/libvstdlib$(SHLIBSUFFIX).$(SHLIBEXT) .; fi
+	if [ ! -f "libsteam_api.$(SHLIBEXT)" ]; then ln -fs $(LIB_DIR)/libsteam_api.$(SHLIBEXT) .; fi
 
 vcpm: check
 	if [ ! -e "vcpm" ]; then $(MAKE) -f $(MAKE_VCPM) $(BASE_DEFINES);fi
diff --git a/mathlib/imagequant.cpp b/mathlib/imagequant.cpp
index bdba52a6..b84d2c5c 100644
--- a/mathlib/imagequant.cpp
+++ b/mathlib/imagequant.cpp
@@ -6,6 +6,7 @@
 //
 //=============================================================================//
 #include <quantize.h>
+#include <tier0/basetypes.h>
 
 #define N_EXTRAVALUES 1
 #define N_DIMENSIONS (3+N_EXTRAVALUES)
diff --git a/mathlib/quantize.cpp b/mathlib/quantize.cpp
index dbaf15f2..2c8c12e5 100644
--- a/mathlib/quantize.cpp
+++ b/mathlib/quantize.cpp
@@ -21,6 +21,8 @@
 
 #include <math.h>
 
+#include <tier0/basetypes.h>
+
 static int current_ndims;
 static struct QuantizedValue *current_root;
 static int current_ssize;
diff --git a/mathlib/sse.cpp b/mathlib/sse.cpp
index d524d2b7..d39c24f8 100644
--- a/mathlib/sse.cpp
+++ b/mathlib/sse.cpp
@@ -172,7 +172,7 @@ float _SSE_RSqrtFast(float x)
 {
 	Assert( s_bMathlibInitialized );
 
-	float rroot;
+	float rroot = 0.0f;
 #ifdef _WIN32
 	_asm
 	{
diff --git a/public/tier0/fasttimer.h b/public/tier0/fasttimer.h
index 0678ebd6..d59a93a5 100644
--- a/public/tier0/fasttimer.h
+++ b/public/tier0/fasttimer.h
@@ -233,8 +233,8 @@ private:
 	unsigned	m_nIters;
 	CCycleCount m_Total;
 	CCycleCount	m_Peak;
-	bool		m_fReport;
-	const tchar *m_pszName;
+//	bool		m_fReport;
+//	const tchar *m_pszName;
 };
 
 // -------------------------------------------------------------------------- // 
diff --git a/public/tier1/CommandBuffer.h b/public/tier1/CommandBuffer.h
index 0a3c4433..da8a1c15 100644
--- a/public/tier1/CommandBuffer.h
+++ b/public/tier1/CommandBuffer.h
@@ -113,7 +113,7 @@ private:
 	bool ParseArgV0( CUtlBuffer &buf, char *pArgv0, int nMaxLen, const char **pArgs );
 
 	char	m_pArgSBuffer[ ARGS_BUFFER_LENGTH ];
-	int		m_nLastUsedArgSSize;
+//	int		m_nLastUsedArgSSize;
 	int		m_nArgSBufferSize;
 	CUtlFixedLinkedList< Command_t >	m_Commands;
 	int		m_nCurrentTick;
diff --git a/public/tier1/utlblockmemory.h b/public/tier1/utlblockmemory.h
index 8d174466..7f08c40b 100644
--- a/public/tier1/utlblockmemory.h
+++ b/public/tier1/utlblockmemory.h
@@ -336,7 +336,6 @@ void CUtlBlockMemory<T,I>::Purge( int numElements )
 	}
 
 	int nBlockSize = NumElementsInBlock();
-	int nBlocksOld = m_nBlocks;
 	int nBlocks = ( numElements + nBlockSize - 1 ) / nBlockSize;
 
 	// If the number of blocks is the same as the allocated number of blocks, we are done.
diff --git a/tier1/checksum_md5.cpp b/tier1/checksum_md5.cpp
index d41f1de2..0c4aeefa 100644
--- a/tier1/checksum_md5.cpp
+++ b/tier1/checksum_md5.cpp
@@ -232,7 +232,7 @@ void MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5Context_t *ctx)
     MD5Transform(ctx->buf, (unsigned int *) ctx->in);
     //byteReverse((unsigned char *) ctx->buf, 4);
     memcpy(digest, ctx->buf, MD5_DIGEST_LENGTH);
-    memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
+    memset(ctx, 0, sizeof(MD5Context_t));        /* In case it's sensitive */
 }
 
 //-----------------------------------------------------------------------------
diff --git a/tier1/datamanager.cpp b/tier1/datamanager.cpp
index 24935280..fd3ddf1a 100644
--- a/tier1/datamanager.cpp
+++ b/tier1/datamanager.cpp
@@ -122,8 +122,6 @@ unsigned int CDataManagerBase::FlushAll()
 unsigned int CDataManagerBase::Purge( unsigned int nBytesToPurge )
 {
 	unsigned int nTargetSize = MemUsed_Inline() - nBytesToPurge;
-	if ( nTargetSize < 0 )
-		nTargetSize = 0;
 	unsigned int nImpliedCapacity = MemTotal_Inline() - nTargetSize;
 	return EnsureCapacity( nImpliedCapacity );
 }
diff --git a/tier1/mempool.cpp b/tier1/mempool.cpp
index 14663a39..18b9007a 100644
--- a/tier1/mempool.cpp
+++ b/tier1/mempool.cpp
@@ -4,6 +4,7 @@
 //
 //===========================================================================//
 
+#include "tier0/basetypes.h"
 #include "mempool.h"
 #include <stdio.h>
 #ifdef __APPLE__
diff --git a/tier1/strtools.cpp b/tier1/strtools.cpp
index 3188f209..76b6da44 100644
--- a/tier1/strtools.cpp
+++ b/tier1/strtools.cpp
@@ -226,7 +226,7 @@ char *V_strnlwr(char *s, size_t count)
 	if ( !s )
 		return s;
 
-	while ( --count >= 0 )
+	while ( count-- )
 	{
 		if ( !*s )
 			break;