diff --git a/linux_sdk/Makefile b/linux_sdk/Makefile
index 84095e08..96bba24e 100644
--- a/linux_sdk/Makefile
+++ b/linux_sdk/Makefile
@@ -30,12 +30,13 @@ 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
-CPP_LIB = "libstdc++.a libgcc_eh.a"
 
 # put any compiler flags you want passed here
 USER_CFLAGS =
@@ -56,7 +57,16 @@ DEBUG = false
 #############################################################################
 # Things below here shouldn't need to be altered
 #############################################################################
-OS := $(shell uname -s)
+IS_CLANG := $(shell $(CPP) --version | head -1 | grep clang > /dev/null && echo "1" || echo "0")
+
+ifeq "$(IS_CLANG)" "1"
+CPP_MAJOR := $(shell $(CPP) --version | grep clang | sed "s/.*version \([0-9]\)*\.[0-9]*.*/\1/")
+CPP_MINOR := $(shell $(CPP) --version | grep clang | sed "s/.*version [0-9]*\.\([0-9]\)*.*/\1/")
+else
+CPP_MAJOR := $(shell $(CPP) -dumpversion >&1 | cut -b1)
+CPP_MINOR := $(shell $(CPP) -dumpversion >&1 | cut -b3)
+endif
+
 MAKE = make
 AR = "ar rvs"
 
@@ -80,20 +90,30 @@ ARCH = i486
 ARCH_CFLAGS = -mtune=i686 -march=pentium3 -mmmx -msse -msse2 -m32
 
 ifeq "$(OS)" "Darwin"
-DEFINES = -D_OSX -DOSX
+DEFINES = -D_OSX -DOSX -D_DLL_EXT=.dylib
 ARCH_CFLAGS += -mmacosx-version-min=10.7
+SHLIBEXT = dylib
+SHLIBLDFLAGS = -dynamiclib -mmacosx-version-min=10.7
+SHLIBSUFFIX =
 else
-DEFINES = -D_LINUX -DLINUX
+DEFINES = -D_LINUX -DLINUX -D_DLL_EXT=.so
+SHLIBEXT = so
+SHLIBLDFLAGS = -shared -Wl,-Map,$@_map.txt
+SHLIBSUFFIX =
 endif
 
-DEFINES += -DCOMPILER_GCC -DPOSIX -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
+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 -DPOSIX -DGNUC -DCOMPILER_GCC -DNO_MALLOC_OVERRIDE
 UNDEF = -Usprintf -Ustrncpy -UPROTECTED_THINGS_ENABLE
 
-BASE_CFLAGS = -fno-strict-aliasing -Wall -Werror -Wno-conversion -Wno-overloaded-virtual -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-unknown-pragmas -Wno-unused
 SHLIBCFLAGS = -fPIC
-SHLIBLDFLAGS = -shared -Wl,-Map,$@_map.txt -Wl
+
+# Clang >= 3 || GCC >= 4.7
+ifeq "$(shell expr $(IS_CLANG) \& $(CPP_MAJOR) \>= 3 \| $(CPP_MAJOR) \>= 4 \& $(CPP_MINOR) \>= 7)" "1"
+BASE_CFLAGS += -Wno-delete-non-virtual-dtor -Wno-narrowing
+endif
 
 # Flags passed to the c compiler
 CFLAGS = $(DEFINES) $(ARCH_CFLAGS) -O3 $(BASE_CFLAGS)
@@ -109,7 +129,7 @@ DBG_CFLAGS = "$(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) \
@@ -133,10 +153,10 @@ check:
 	cd $(BUILD_DIR)
 	if [ ! -e "$(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 $(SRCDS_DIR)/bin/steam_api_i486.so .; fi
+	if [ ! -e "$(LIB_DIR)/interfaces_i486.a" ]; then $(MAKE) interfaces;fi
+	if [ ! -f "libtier0$(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/public/appframework/IAppSystemGroup.h b/public/appframework/IAppSystemGroup.h
index 89c4d8e6..b5cad8ba 100644
--- a/public/appframework/IAppSystemGroup.h
+++ b/public/appframework/IAppSystemGroup.h
@@ -23,7 +23,7 @@
 #include "tier1/interface.h"
 #include "tier1/utlvector.h"
 #include "tier1/utldict.h"
-#include "tier1/utlstringmap.h"
+#include "tier1/UtlStringMap.h"
 #include "IAppSystem.h"
 
 //-----------------------------------------------------------------------------
diff --git a/public/datacache/idatacache.h b/public/datacache/idatacache.h
index 0ff98db4..9c9bc509 100644
--- a/public/datacache/idatacache.h
+++ b/public/datacache/idatacache.h
@@ -351,6 +351,7 @@ public:
 		case DC_AGE_DISCARD:
 		case DC_FLUSH_DISCARD:
 		case DC_REMOVED:
+		default:
 			Assert ( 0 );
 			return false;
 		}
@@ -536,6 +537,7 @@ public:
 		case DC_AGE_DISCARD:
 		case DC_FLUSH_DISCARD:
 		case DC_REMOVED:
+		default:
 			STORAGE_TYPE *p = (STORAGE_TYPE *)notification.clientId;
 			p->DestroyResource();
 			return true;
diff --git a/public/filesystem/IQueuedLoader.h b/public/filesystem/IQueuedLoader.h
index 428a05e8..8f5f8c9f 100644
--- a/public/filesystem/IQueuedLoader.h
+++ b/public/filesystem/IQueuedLoader.h
@@ -12,7 +12,7 @@
 #endif
 
 #include "tier0/platform.h"
-#include "appframework/iappsystem.h"
+#include "appframework/IAppSystem.h"
 
 enum LoaderError_t
 {
diff --git a/public/filesystem_init.cpp b/public/filesystem_init.cpp
index 6a9f45f3..eb1f18ec 100644
--- a/public/filesystem_init.cpp
+++ b/public/filesystem_init.cpp
@@ -23,9 +23,8 @@
 #include "tier1/strtools.h"
 #include "filesystem_init.h"
 #include "tier0/icommandline.h"
-#include "tier0/stacktools.h"
-#include "keyvalues.h"
-#include "appframework/iappsystemgroup.h"
+#include "KeyValues.h"
+#include "appframework/IAppSystemGroup.h"
 #include "tier1/smartptr.h"
 #if defined( _X360 )
 #include "xbox\xbox_win32stubs.h"
@@ -546,7 +545,7 @@ bool IsLowViolenceBuild( void )
 	return retVal;
 #elif POSIX
 	return false;
-#elif
+#else
 	#error "Fix me"
 #endif
 }
@@ -620,21 +619,6 @@ static void FileSystem_AddLoadedSearchPath(
 	initInfo.m_pFileSystem->AddSearchPath( fullLocationPath, pPathID, PATH_ADD_TO_TAIL );
 }
 
-
-bool FileSystem_IsHldsUpdateToolDedicatedServer()
-{
-	// To determine this, we see if the directory our executable was launched from is "orangebox".
-	// We only are under "orangebox" if we're run from hldsupdatetool.
-	char baseDir[MAX_PATH];
-	if ( !FileSystem_GetBaseDir( baseDir, sizeof( baseDir ) ) )
-		return false;
-
-	V_FixSlashes( baseDir );
-	V_StripTrailingSlash( baseDir );
-	const char *pLastDir = V_UnqualifiedFileName( baseDir );
-	return ( pLastDir && V_stricmp( pLastDir, "orangebox" ) == 0 );
-}
-
 #ifdef ENGINE_DLL
 	extern void FileSystem_UpdateAddonSearchPaths( IFileSystem *pFileSystem );
 #endif
@@ -690,14 +674,6 @@ FSReturnCode_t FileSystem_LoadSearchPaths( CFSSearchPathsInit &initInfo )
 			// Add the Orange-box path (which also will include whatever the depots mapped in as well if we're 
 			// running a Steam-launched app).
 			FileSystem_AddLoadedSearchPath( initInfo, pPathID, &bFirstGamePath, baseDir, pLocation, bLowViolence );
-
-			if ( FileSystem_IsHldsUpdateToolDedicatedServer() )
-			{			
-				// If we're using the hldsupdatetool dedicated server, then go up a directory to get the ep1-era files too.
-				char ep1EraPath[MAX_PATH];
-				V_snprintf( ep1EraPath, sizeof( ep1EraPath ), "..%c%s", CORRECT_PATH_SEPARATOR, pLocation );
-				FileSystem_AddLoadedSearchPath( initInfo, pPathID, &bFirstGamePath, baseDir, ep1EraPath, bLowViolence );
-			}
 		}
 		else
 		{
diff --git a/public/icvar.h b/public/icvar.h
index ebab8531..00d83c82 100644
--- a/public/icvar.h
+++ b/public/icvar.h
@@ -175,7 +175,7 @@ inline ICvar::Iterator::Iterator(ICvar *icvar)
 
 inline ICvar::Iterator::~Iterator( void )
 {
-	g_pMemAlloc->Free(m_pIter);
+	free(m_pIter);
 }
 
 inline void ICvar::Iterator::SetFirst( void )
diff --git a/public/tier0/memalloc.h b/public/tier0/memalloc.h
index 627aaf95..a189ab64 100644
--- a/public/tier0/memalloc.h
+++ b/public/tier0/memalloc.h
@@ -36,9 +36,11 @@
 // Undefine this if using a compiler lacking threadsafe RTTI (like vc6)
 #define MEM_DEBUG_CLASSNAME 1
 
-#if !defined(STEAM) && !defined(NO_MALLOC_OVERRIDE)
-
 #include <stddef.h>
+#if defined(OSX)
+#include <malloc/malloc.h>
+#endif
+
 #ifdef LINUX
 #undef offsetof
 #define offsetof(s,m)	(size_t)&(((s *)0)->m)
@@ -46,6 +48,8 @@
 
 #include "tier0/mem.h"
 
+#if !defined(STEAM) && !defined(NO_MALLOC_OVERRIDE)
+
 struct _CrtMemState;
 
 #define MEMALLOC_VERSION 1
@@ -488,15 +492,59 @@ struct MemAllocFileLine_t
 
 //-----------------------------------------------------------------------------
 
+#elif defined( POSIX )
+
+#if defined( OSX )
+// Mac always aligns allocs, don't need to call posix_memalign which doesn't exist in 10.5.8 which TF2 still needs to run on
+//inline void *memalign(size_t alignment, size_t size) {void *pTmp=NULL; posix_memalign(&pTmp, alignment, size); return pTmp;}
+inline void *memalign(size_t alignment, size_t size) {void *pTmp=NULL; pTmp = malloc(size); return pTmp;}
+#endif
+
+inline void *_aligned_malloc( size_t nSize, size_t align )															{ return memalign( align, nSize ); }
+inline void _aligned_free( void *ptr )																				{ free( ptr ); }
+
+inline void *MemAlloc_Alloc( size_t nSize, const char *pFileName = NULL, int nLine = 0 )							{ return malloc( nSize ); }
+inline void MemAlloc_Free( void *ptr, const char *pFileName = NULL, int nLine = 0 )									{ free( ptr ); }
+
+inline void *MemAlloc_AllocAligned( size_t size, size_t align, const char *pszFile = NULL, int nLine = 0  )	        { return memalign( align, size ); }
+inline void *MemAlloc_AllocAlignedFileLine( size_t size, size_t align, const char *pszFile = NULL, int nLine = 0 )	{ return memalign( align, size ); }
+inline void MemAlloc_FreeAligned( void *pMemBlock, const char *pszFile = NULL, int nLine = 0 ) 						{ free( pMemBlock ); }
+
+#if defined( OSX )
+inline size_t _msize( void *ptr )																					{ return malloc_size( ptr ); }
+#else
+inline size_t _msize( void *ptr )																					{ return malloc_usable_size( ptr ); }
+#endif
+
+inline void *MemAlloc_ReallocAligned( void *ptr, size_t size, size_t align )
+{
+	void *ptr_new_aligned = memalign( align, size );
+
+	if( ptr_new_aligned )
+	{
+		size_t old_size = _msize( ptr );
+		size_t copy_size = ( size < old_size ) ? size : old_size;
+
+		memcpy( ptr_new_aligned, ptr, copy_size );
+		free( ptr );
+	}
+
+	return ptr_new_aligned;
+}
+#else
+#define MemAlloc_GetDebugInfoSize() g_pMemAlloc->GetDebugInfoSize()
+#define MemAlloc_SaveDebugInfo( pvDebugInfo ) g_pMemAlloc->SaveDebugInfo( pvDebugInfo )
+#define MemAlloc_RestoreDebugInfo( pvDebugInfo ) g_pMemAlloc->RestoreDebugInfo( pvDebugInfo )
+#define MemAlloc_InitDebugInfo( pvDebugInfo, pchRootFileName, nLine ) g_pMemAlloc->InitDebugInfo( pvDebugInfo, pchRootFileName, nLine )
+
 #endif // !STEAM && !NO_MALLOC_OVERRIDE
 
 //-----------------------------------------------------------------------------
 
 #if !defined(STEAM) && defined(NO_MALLOC_OVERRIDE)
-#include <malloc.h>
-
 #define MEM_ALLOC_CREDIT_(tag)	((void)0)
 #define MEM_ALLOC_CREDIT()	MEM_ALLOC_CREDIT_(__FILE__)
+#define MEM_ALLOC_CREDIT_FUNCTION()
 #define MEM_ALLOC_CREDIT_CLASS()
 #define MEM_ALLOC_CLASSNAME(type) NULL
 
@@ -507,28 +555,6 @@ struct MemAllocFileLine_t
 #define MemAlloc_RegisterExternalAllocation( tag, p, size ) ((void)0)
 #define MemAlloc_RegisterExternalDeallocation( tag, p, size ) ((void)0)
 
-inline void *MemAlloc_AllocAligned( size_t size, size_t align )
-{
-	return (void *)_aligned_malloc( size, align );
-}
-inline void *MemAlloc_AllocAligned( size_t size, size_t align, const char *pszFile, int nLine )
-{
-	pszFile = pszFile;
-	nLine = nLine;
-	return (void *)_aligned_malloc( size, align );
-}
-
-inline void MemAlloc_FreeAligned( void *pMemBlock )
-{
-	_aligned_free( pMemBlock );
-}
-inline void MemAlloc_FreeAligned( void *pMemBlock, const char *pszFile, int nLine )
-{
-	pszFile = pszFile;
-	nLine = nLine;
-	_aligned_free( pMemBlock );
-}
-
 #endif // !STEAM && NO_MALLOC_OVERRIDE
 
 //-----------------------------------------------------------------------------
diff --git a/public/tier1/fmtstr.h b/public/tier1/fmtstr.h
index 39df48ed..4ec3526d 100644
--- a/public/tier1/fmtstr.h
+++ b/public/tier1/fmtstr.h
@@ -21,13 +21,13 @@
 //=============================================================================
 
 // using macro to be compatable with GCC
-#define FmtStrVSNPrintf( szBuf, nBufSize, ppszFormat ) \
+#define FmtStrVSNPrintf( szBuf, nBufSize, ppszFormat, lastArg ) \
 	do \
 	{ \
 		int     result; \
 		va_list arg_ptr; \
 	\
-		va_start(arg_ptr, (*(ppszFormat))); \
+		va_start(arg_ptr, lastArg); \
 		result = Q_vsnprintf((szBuf), (nBufSize)-1, (*(ppszFormat)), arg_ptr); \
 		va_end(arg_ptr); \
 	\
@@ -50,26 +50,26 @@ public:
 	// Standard C formatting
 	CFmtStrN(const char *pszFormat, ...) FMTFUNCTION( 2, 3 )
 	{
-		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, &pszFormat);
+		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, &pszFormat, pszFormat);
 	}
 
 	// Use this for pass-through formatting
 	CFmtStrN(const char ** ppszFormat, ...)
 	{
-		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, ppszFormat);
+		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, ppszFormat, ppszFormat);
 	}
 
 	// Explicit reformat
 	const char *sprintf(const char *pszFormat, ...)	FMTFUNCTION( 2, 3 )
 	{
-		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, &pszFormat); 
+		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, &pszFormat, pszFormat); 
 		return m_szBuf;
 	}
 
 	// Use this for pass-through formatting
 	void VSprintf(const char **ppszFormat, ...)
 	{
-		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, ppszFormat);
+		FmtStrVSNPrintf(m_szBuf, SIZE_BUF, ppszFormat, ppszFormat);
 	}
 
 	// Use for access
@@ -81,7 +81,7 @@ public:
 
 	void Clear()								{ m_szBuf[0] = 0; }
 
-	void AppendFormat( const char *pchFormat, ... ) { int nLength = Length(); char *pchEnd = m_szBuf + nLength; FmtStrVSNPrintf( pchEnd, SIZE_BUF - nLength, &pchFormat ); }
+	void AppendFormat( const char *pchFormat, ... ) { int nLength = Length(); char *pchEnd = m_szBuf + nLength; FmtStrVSNPrintf( pchEnd, SIZE_BUF - nLength, &pchFormat, pchFormat ); }
 	void AppendFormatV( const char *pchFormat, va_list args );
 	void Append( const char *pchValue ) { AppendFormat( pchValue ); }
 
diff --git a/public/tier1/smartptr.h b/public/tier1/smartptr.h
index c8d6ffb2..95d0bef3 100644
--- a/public/tier1/smartptr.h
+++ b/public/tier1/smartptr.h
@@ -107,7 +107,7 @@ template < typename T >
 class CArrayAutoPtr : public CPlainAutoPtr < T > // Warning: no polymorphic destructor (delete on base class will be a mistake)
 {
 public:
-	explicit CArrayAutoPtr( T *p = NULL )		{ Attach( p ); }
+	explicit CArrayAutoPtr( T *p = NULL )		{ this->Attach( p ); }
 	~CArrayAutoPtr( void )						{ Delete(); }
 
 public:
diff --git a/public/tier1/utlmemory.h b/public/tier1/utlmemory.h
index 601e722d..72264a02 100644
--- a/public/tier1/utlmemory.h
+++ b/public/tier1/utlmemory.h
@@ -272,7 +272,7 @@ private:
 	char m_Memory[ SIZE*sizeof(T) + nAlignment ];
 };
 
-#ifdef _LINUX
+#if defined(POSIX)
 #define REMEMBER_ALLOC_SIZE_FOR_VALGRIND 1
 #endif