diff --git a/lib/public/tier1.lib b/lib/public/tier1.lib
index b66bc4a1..d382e0e7 100644
Binary files a/lib/public/tier1.lib and b/lib/public/tier1.lib differ
diff --git a/notes.txt b/notes.txt
index e10868f8..5d397b22 100644
--- a/notes.txt
+++ b/notes.txt
@@ -1,35 +1,9 @@
 *********
 * About *
 *********
-This version of the Source/Orange Box SDK attempts to remove as many
-warnings as possible when compiling on Windows or Linux.
-The -fpermissive option has been removed from the Linux makefiles and
--Wall has been added. It is also now possible to cross-compile the SDK
-on 64-bit Linux systems with the addition of the -m32 option.
+This version of the Source SDK is meant only for compiling server plugins for
+the engine that runs Valve's Left 4 Dead game. An official SDK is not yet
+available.
 
-*********
-* Notes *
-*********
-1: A Visual Studio project file for choreoobjects has been added to
-   the choreoobjects directory for the convenience of recompiling this
-   static library for Windows if it ever becomes necessary to do so.
-
-2: Makefiles for choreoobjects, mathlib, and tier1 have been added to
-   the linux_sdk directory for the convenience of recompiling these
-   static libraries for Linux if it ever becomes necessary to do so.
-   
-3: The vmpi directory has been removed as it seems to be an exact copy
-   of the one located in the utils directory. Nothing seems to depend
-   upon the files within it yet.
-
-****************
-* Known Issues *
-****************
-1: The SDK will not compile with GCC 4.3. This will be addressed in a
-   future update.
-   
-2: The SDK may not fully compile with Visual Studio 2008. This will be
-   addressed in a future update.
-
-3: The caption compiler which is located in utils/captioncompiler will
-   not link due to a missing static library (appframework.lib).
+This is a modified version of the Orange Box SDK. Changes to it were reverse
+engineered from the Left 4 Dead engine and game binaries.
diff --git a/public/edict.h b/public/edict.h
index 98875288..47d1a044 100644
--- a/public/edict.h
+++ b/public/edict.h
@@ -59,6 +59,14 @@ public:
 	bool			teamplay;
 	// current maxentities
 	int				maxEntities;
+	
+	// Number of servers spawned (-fork)
+	int				serverCount;
+	
+	// First edict/entity, usually worldspawn (0)
+	// - Replacement for IndexOfEntity: (edict - baseEdict) >> 4
+	// - Replacement for PEntityOfIndex: baseEdict + (entIndex << 4)
+	edict_t			*baseEdict;
 };
 
 inline CGlobalVars::CGlobalVars( bool bIsClient ) : 
diff --git a/public/eiface.h b/public/eiface.h
index fea09c4e..294ea548 100644
--- a/public/eiface.h
+++ b/public/eiface.h
@@ -57,6 +57,7 @@ class CStandardSendProxies;
 class IAchievementMgr;
 class CGamestatsData;
 class CSteamID;
+struct bbox_t;
 
 typedef struct player_info_s player_info_t;
 
@@ -70,7 +71,7 @@ typedef struct player_info_s player_info_t;
 #define DLLEXPORT /* */
 #endif
 
-#define INTERFACEVERSION_VENGINESERVER	"VEngineServer021"
+#define INTERFACEVERSION_VENGINESERVER	"VEngineServer022"
 
 //-----------------------------------------------------------------------------
 // Purpose: Interface the engine exposes to the game DLL
@@ -123,13 +124,12 @@ public:
 	virtual int			GetPlayerUserId( const edict_t *e ) = 0; 
 	virtual const char	*GetPlayerNetworkIDString( const edict_t *e ) = 0;
 
+	virtual bool		IsUserIDInUse ( int userid ) = 0;
+	virtual int			GetLoadingProgressForUserID ( int userid ) = 0;
+
 	// Return the current number of used edict slots
 	virtual int			GetEntityCount( void ) = 0;
-	// Given an edict, returns the entity index
-	virtual int			IndexOfEdict( const edict_t *pEdict ) = 0;
-	// Given and entity index, returns the corresponding edict pointer
-	virtual edict_t		*PEntityOfEntIndex( int iEntIndex ) = 0;
-	
+
 	// Get stats info interface for a client netchannel
 	virtual INetChannelInfo* GetPlayerNetInfo( int playerIndex ) = 0;
 	
@@ -265,6 +265,7 @@ public:
 
 	// Print a message to the server log file
 	virtual void		LogPrint( const char *msg ) = 0;
+	virtual bool		IsLogEnabled( void ) = 0;
 
 	// Builds PVS information for an entity
 	virtual void		BuildEntityClusterList( edict_t *pEdict, PVSInfo_t *pPVSInfo ) = 0;
@@ -311,7 +312,7 @@ public:
 
 	// Is the engine in Commentary mode?
 	virtual int			IsInCommentaryMode( void ) = 0;
-	
+	virtual bool		IsLevelMainMenuBackground( void ) = 0;
 
 	// Mark some area portals as open/closed. It's more efficient to use this
 	// than a bunch of individual SetAreaPortalState calls.
@@ -338,6 +339,10 @@ public:
 	// Name of most recently load .sav file
 	virtual char const *GetMostRecentlyLoadedFileName() = 0;
 	virtual char const *GetSaveFileName() = 0;
+	virtual void WriteSavegameScreenshot( const char *filename ) = 0;
+	
+	virtual int GetLightForPointListenServerOnly(const Vector &, bool, Vector *) = 0;
+	virtual int TraceLightingListenServerOnly(const Vector &, const Vector &, Vector *, Vector *) = 0;
 
 	// Matchmaking
 	virtual void MultiplayerEndGame() = 0;
@@ -352,6 +357,7 @@ public:
 	virtual int	GetAppID() = 0;
 	
 	virtual bool IsLowViolence() = 0;
+	virtual bool IsAnyClientLowViolence() = 0;
 	
 	// Call this to find out the value of a cvar on the client.
 	//
@@ -370,16 +376,32 @@ public:
 	// Returns true if this client has been fully authenticated by Steam
 	virtual bool IsClientFullyAuthenticated( edict_t *pEdict ) = 0;
 
-	// This makes the host run 1 tick per frame instead of checking the system timer to see how many ticks to run in a certain frame.
-	// i.e. it does the same thing timedemo does.
-	virtual void SetDedicatedServerBenchmarkMode( bool bBenchmarkMode ) = 0;
+	virtual bool IsSplitScreenPlayer( int ) = 0;
+	virtual int GetSplitScreenPlayerAttachToEdict( int ) = 0;
+	virtual int GetNumSplitScreenUsersAttachedToEdict( int ) = 0;
+	virtual int GetSplitScreenPlayerForEdict( int, int ) = 0;
+	
+	virtual bool IsOverrideLoadGameEntsOn() = 0;
+	virtual void ForceFlushEntity( int ) = 0;
+	
+	virtual void *GetSinglePlayerSharedMemorySpace( char const * ) = 0;
+	
+	virtual void *AllocLevelStaticData( unsigned int ) = 0;
+	virtual int GetClusterCount() = 0;
+	virtual void *GetAllClusterBounds( bbox_t *, int ) = 0;
+	
+	virtual bool IsCreatingReslist() = 0;
+	virtual bool IsCreatingXboxReslist() = 0;
+	virtual bool IsDedicatedServerForXbox() = 0;
+	
+	virtual void Pause( bool, bool ) = 0;
 
 	// Methods to set/get a gamestats data container so client & server running in same process can send combined data
 	virtual void SetGamestatsData( CGamestatsData *pGamestatsData ) = 0;
 	virtual CGamestatsData *GetGamestatsData() = 0;
-
-	// Returns the SteamID of the specified player. It'll be NULL if the player hasn't authenticated yet.
-	virtual const CSteamID	*GetClientSteamID( edict_t *pPlayerEdict ) = 0;
+	
+	virtual void HostValidateSession() = 0;
+	virtual void RefreshScreenIfNecessary() = 0;
 };
 
 #define INTERFACEVERSION_SERVERGAMEDLL_VERSION_4	"ServerGameDLL004"
@@ -487,6 +509,12 @@ public:
 	// iCookie is the value returned by IServerPluginHelpers::StartQueryCvarValue.
 	// Added with version 2 of the interface.
 	virtual void			OnQueryCvarValueFinished( QueryCvarCookie_t iCookie, edict_t *pPlayerEntity, EQueryCvarValueStatus eStatus, const char *pCvarName, const char *pCvarValue ) = 0;
+	
+	virtual void			PostToolsInit( void ) = 0;
+	virtual void			ApplyGameSettings( KeyValues * ) = 0;
+	virtual const char *	GetGameModeConfigFile( int ) = 0;
+	virtual int				GameGameModePlayerSlots( int ) = 0;
+	virtual void			GetMatchmakingTags( char *, unsigned int ) = 0; 
 };
 
 //-----------------------------------------------------------------------------
@@ -505,9 +533,6 @@ abstract_class IServerGameEnts
 public:
 	virtual					~IServerGameEnts()	{}
 
-	// Only for debugging. Set the edict base so you can get an edict's index in the debugger while debugging the game .dll
-	virtual void			SetDebugEdictBase(edict_t *base) = 0;
-	
 	// The engine wants to mark two entities as touching
 	virtual void			MarkEntitiesAsTouching( edict_t *e1, edict_t *e2 ) = 0;
 
@@ -524,6 +549,8 @@ public:
 	// This is also where an entity can force other entities to be transmitted if it refers to them
 	// with ehandles.
 	virtual void			CheckTransmit( CCheckTransmitInfo *pInfo, const unsigned short *pEdictIndices, int nEdicts ) = 0;
+	
+	virtual void			PrepareForFullUpdate( edict_t * ) = 0;
 };
 
 #define INTERFACEVERSION_SERVERGAMECLIENTS		"ServerGameClients003"
@@ -582,9 +609,15 @@ public:
 	// Anything this game .dll wants to add to the bug reporter text (e.g., the entity/model under the picker crosshair)
 	//  can be added here
 	virtual void			GetBugReportInfo( char *buf, int buflen ) = 0;
+	
+	virtual void			ClientVoice( edict_t * ) = 0;
 
 	// A user has had their network id setup and validated 
 	virtual void			NetworkIDValidated( const char *pszUserName, const char *pszNetworkID ) = 0;
+	
+	virtual int 			GetMaxSplitscreenPlayers( void ) = 0;
+	
+	virtual int				GetMaxHumanPlayers( void ) = 0;
 };
 
 #define INTERFACEVERSION_UPLOADGAMESTATS		"ServerUploadGameStats001"
diff --git a/public/engine/IEngineSound.h b/public/engine/IEngineSound.h
index 25bcef2b..07380b6f 100644
--- a/public/engine/IEngineSound.h
+++ b/public/engine/IEngineSound.h
@@ -59,6 +59,9 @@ public:
 	virtual bool PrecacheSound( const char *pSample, bool bPreload = false, bool bIsUISound = false ) = 0;
 	virtual bool IsSoundPrecached( const char *pSample ) = 0;
 	virtual void PrefetchSound( const char *pSample ) = 0;
+	
+	// Client only
+	virtual bool IsLoopingSound( const char *pSample ) = 0;
 
 	// Just loads the file header and checks for duration (not hooked up for .mp3's yet)
 	// Is accessible to server and client though
@@ -116,6 +119,9 @@ public:
 	virtual void	PrecacheSentenceGroup( const char *pGroupName ) = 0;
 	virtual void	NotifyBeginMoviePlayback() = 0;
 	virtual void	NotifyEndMoviePlayback() = 0;
+	
+	// Client only
+	virtual float	GetSoundChannelVolume( const char *, float &, float & ) = 0;
 };
 
 
diff --git a/public/engine/IEngineTrace.h b/public/engine/IEngineTrace.h
index 3c729f71..61d7d7fd 100644
--- a/public/engine/IEngineTrace.h
+++ b/public/engine/IEngineTrace.h
@@ -23,7 +23,6 @@ class CGameTrace;
 typedef CGameTrace trace_t;
 class ICollideable;
 class QAngle;
-class CTraceListData;
 class CPhysCollide;
 struct cplane_t;
 
@@ -45,6 +44,16 @@ public:
 	virtual TraceType_t	GetTraceType() const = 0;
 };
 
+abstract_class ITraceListData
+{
+public:
+	virtual ~ITraceListData() {};
+
+	virtual void Reset() = 0;
+	virtual bool IsEmpty() = 0;
+	virtual bool CanTraceRay( const Ray_t &ray ) = 0;
+};
+
 
 //-----------------------------------------------------------------------------
 // Classes are expected to inherit these + implement the ShouldHitEntity method
@@ -129,8 +138,9 @@ abstract_class IEngineTrace
 {
 public:
 	// Returns the contents mask + entity at a particular world-space position
-	virtual int		GetPointContents( const Vector &vecAbsPosition, IHandleEntity** ppEntity = NULL ) = 0;
+	virtual int		GetPointContents( const Vector &vecAbsPosition, int, IHandleEntity** ppEntity = NULL ) = 0;
 	
+	virtual int		GetPointContents_WorldOnly( const Vector &vecAbsPosition, int ) = 0;
 	// Get the point contents, but only test the specific entity. This works
 	// on static props and brush models.
 	//
@@ -148,9 +158,9 @@ public:
 	virtual void	TraceRay( const Ray_t &ray, unsigned int fMask, ITraceFilter *pTraceFilter, trace_t *pTrace ) = 0;
 
 	// A version that sets up the leaf and entity lists and allows you to pass those in for collision.
-	virtual void	SetupLeafAndEntityListRay( const Ray_t &ray, CTraceListData &traceData ) = 0;
-	virtual void    SetupLeafAndEntityListBox( const Vector &vecBoxMin, const Vector &vecBoxMax, CTraceListData &traceData ) = 0;
-	virtual void	TraceRayAgainstLeafAndEntityList( const Ray_t &ray, CTraceListData &traceData, unsigned int fMask, ITraceFilter *pTraceFilter, trace_t *pTrace ) = 0;
+	virtual void	SetupLeafAndEntityListRay( const Ray_t &ray, ITraceListData *traceData ) = 0;
+	virtual void    SetupLeafAndEntityListBox( const Vector &vecBoxMin, const Vector &vecBoxMax, ITraceListData *traceData ) = 0;
+	virtual void	TraceRayAgainstLeafAndEntityList( const Ray_t &ray, ITraceListData *traceData, unsigned int fMask, ITraceFilter *pTraceFilter, trace_t *pTrace ) = 0;
 
 	// A version that sweeps a collideable through the world
 	// abs start + abs end represents the collision origins you want to sweep the collideable through
@@ -185,6 +195,9 @@ public:
 
 	// Walks bsp to find the leaf containing the specified point
 	virtual int GetLeafContainingPoint( const Vector &ptTest ) = 0;
+	
+	virtual ITraceListData *AllocTraceListData( void ) = 0;
+	virtual void FreeTraceListData( ITraceListData *traceData ) = 0;
 };
 
 
diff --git a/public/filesystem.h b/public/filesystem.h
index f87fb72b..12ce2dc6 100644
--- a/public/filesystem.h
+++ b/public/filesystem.h
@@ -736,6 +736,17 @@ public:
 
 	// Installs a callback used to display a dirty disk dialog
 	virtual void			InstallDirtyDiskReportFunc( FSDirtyDiskReportFunc_t func ) = 0;
+	
+	virtual bool			IsLaunchedFromXboxHDD( void ) = 0;
+	virtual bool			IsInstalledToXboxHDDCache( void ) = 0;
+	virtual bool			IsDVDHosted( void ) = 0;
+	virtual bool			IsInstallAllowed( void ) = 0;
+	virtual void			GetSearchPathID( char *, int ) = 0;
+	virtual bool			FixupSearchPathsAfterInstall( void ) = 0;
+	
+	virtual FSDirtyDiskReportFunc_t	GetDirtyDiskReportFunc( void ) = 0;
+	
+	virtual int				AddVPKFile( const char *file ) = 0;
 };
 
 //-----------------------------------------------------------------------------
diff --git a/public/filesystem_passthru.h b/public/filesystem_passthru.h
index 5a0bc2fe..0885a790 100644
--- a/public/filesystem_passthru.h
+++ b/public/filesystem_passthru.h
@@ -229,6 +229,14 @@ public:
 	virtual void SetWhitelistSpewFlags( int spewFlags )
 		{ m_pFileSystemPassThru->SetWhitelistSpewFlags( spewFlags ); }
 	virtual void InstallDirtyDiskReportFunc( FSDirtyDiskReportFunc_t func ) { m_pFileSystemPassThru->InstallDirtyDiskReportFunc( func ); }
+	virtual bool IsLaunchedFromXboxHDD() { return m_pFileSystemPassThru->IsLaunchedFromXboxHDD(); }
+	virtual bool IsInstalledToXboxHDDCache() { return m_pFileSystemPassThru->IsInstalledToXboxHDDCache(); }
+	virtual bool IsDVDHosted() { return m_pFileSystemPassThru->IsDVDHosted(); }
+	virtual bool IsInstallAllowed() { return m_pFileSystemPassThru->IsInstallAllowed(); }
+	virtual void GetSearchPathID( char *a, int b ) { m_pFileSystemPassThru->GetSearchPathID(a, b); }
+	virtual bool FixupSearchPathsAfterInstall() { return m_pFileSystemPassThru->FixupSearchPathsAfterInstall(); }
+	virtual FSDirtyDiskReportFunc_t	GetDirtyDiskReportFunc() { return m_pFileSystemPassThru->GetDirtyDiskReportFunc(); }
+	virtual int	AddVPKFile( const char *file ) { return m_pFileSystemPassThru->AddVPKFile(file); }
 
 protected:
 	IFileSystem *m_pFileSystemPassThru;
diff --git a/public/iclient.h b/public/iclient.h
index bd5a70ec..8ba4bc02 100644
--- a/public/iclient.h
+++ b/public/iclient.h
@@ -23,7 +23,7 @@ public:
 	virtual	~IClient() {}
 
 	// connect client
-	virtual void	Connect(const char * szName, int nUserID, INetChannel *pNetChannel, bool bFakePlayer) = 0;
+	virtual void	Connect(const char * szName, int nUserID, INetChannel *pNetChannel, bool bFakePlayer, CUtlVector< NetMessageCvar_t > *) = 0;
 
 	// set the client in a pending state waiting for a new game
 	virtual void	Inactivate( void ) = 0;
@@ -80,6 +80,12 @@ public:
 	virtual bool	IsProximityHearingClient(int index) const = 0;
 
 	virtual void	SetMaxRoutablePayloadSize( int nMaxRoutablePayloadSize ) = 0;
+	
+	virtual bool	IsSplitScreenUser( void ) = 0;
+	virtual bool	CheckConnect ( void ) = 0;
+	virtual bool	IsLowViolenceClient( void ) = 0;
+	virtual int		GetSplitScreenOwner( void ) = 0;
+	virtual int		GetNumPlayers( void ) = 0;
 };
 
 #endif // ICLIENT_H
diff --git a/public/icvar.h b/public/icvar.h
index d3ee53af..cae71bc8 100644
--- a/public/icvar.h
+++ b/public/icvar.h
@@ -75,10 +75,6 @@ public:
 	virtual ConCommand		*FindCommand( const char *name ) = 0;
 	virtual const ConCommand *FindCommand( const char *name ) const = 0;
 
-	// Get first ConCommandBase to allow iteration
-	virtual ConCommandBase	*GetCommands( void ) = 0;
-	virtual const ConCommandBase *GetCommands( void ) const = 0;
-
 	// Install a global change callback (to be called when any convar changes) 
 	virtual void			InstallGlobalChangeCallback( FnChangeCallback_t callback ) = 0;
 	virtual void			RemoveGlobalChangeCallback( FnChangeCallback_t callback ) = 0;
@@ -102,9 +98,23 @@ public:
 #if defined( _X360 )
 	virtual void			PublishToVXConsole( ) = 0;
 #endif
+
+	virtual void SetMaxSplitScreenSlots( int ) = 0;
+	virtual int GetMaxSplitScreenSlots() const = 0;
+	virtual void AddSplitScreenConVars() = 0;
+	virtual void RemoveSplitScreenConVars( int ) = 0;
+	virtual int GetConsoleDisplayFuncCount() const = 0;
+	virtual void GetConsoleText( int, char *, unsigned int ) const = 0;
+	virtual bool IsMaterialThreadSetAllowed() const = 0;
+	virtual void QueueMaterialThreadSetValue( ConVar *, const char * ) = 0;
+	virtual void QueueMaterialThreadSetValue( ConVar *, int ) = 0;
+	virtual void QueueMaterialThreadSetValue( ConVar *, float ) = 0;
+	virtual bool HasQueuedMaterialThreadConVarSets() const = 0;
+	virtual int ProcessQueuedMaterialThreadConVarSets() = 0;
+	virtual void FactoryInternalIterator() = 0;
 };
 
-#define CVAR_INTERFACE_VERSION "VEngineCvar004"
+#define CVAR_INTERFACE_VERSION "VEngineCvar007"
 
 
 //-----------------------------------------------------------------------------
diff --git a/public/igameevents.h b/public/igameevents.h
index f5a90fe6..f4924770 100644
--- a/public/igameevents.h
+++ b/public/igameevents.h
@@ -93,6 +93,10 @@ public:
 	// FireEvent is called by EventManager if event just occured
 	// KeyValue memory will be freed by manager if not needed anymore
 	virtual void FireGameEvent( IGameEvent *event ) = 0;
+	virtual int GetEventDebugID( void )
+	{
+		return 0;
+	}
 };
 
 abstract_class IGameEventManager2 : public IBaseInterface
@@ -117,7 +121,7 @@ public:
 
 	// create an event by name, but doesn't fire it. returns NULL is event is not
 	// known or no listener is registered for it. bForce forces the creation even if no listener is active
-	virtual IGameEvent *CreateEvent( const char *name, bool bForce = false ) = 0;
+	virtual IGameEvent *CreateEvent( const char *name, bool bForce = false, int *unknown=NULL) = 0;
 
 	// fires a server event created earlier, if bDontBroadcast is set, event is not send to clients
 	virtual bool FireEvent( IGameEvent *event, bool bDontBroadcast = false ) = 0;
diff --git a/public/networkstringtabledefs.h b/public/networkstringtabledefs.h
index a0eeaf52..0f3ede04 100644
--- a/public/networkstringtabledefs.h
+++ b/public/networkstringtabledefs.h
@@ -58,6 +58,24 @@ public:
 	virtual void			SetStringChangedCallback( void *object, pfnStringChanged changeFunc ) = 0;
 };
 
+class INetworkStringDict
+{
+public:
+
+	virtual					~INetworkStringDict( void ) {};
+	
+	virtual int				Count( void ) = 0;
+	virtual void			Purge( void ) = 0;
+	virtual const char 		*String( int index ) = 0;
+	virtual bool			IsValidIndex( int index ) = 0;
+	virtual int				Insert( const char *string ) = 0;
+	virtual int				Find( const char *string ) = 0;
+	virtual void			UpdateDictionary( int ) = 0;
+	virtual int				DictionaryIndex( int ) = 0;
+	virtual int				Element( int ) = 0;
+	virtual int				Element( int ) const = 0;
+};
+
 class INetworkStringTableContainer
 {
 public:
@@ -65,7 +83,7 @@ public:
 	virtual					~INetworkStringTableContainer( void ) {};
 	
 	// table creation/destruction
-	virtual INetworkStringTable	*CreateStringTable( const char *tableName, int maxentries, int userdatafixedsize = 0, int userdatanetworkbits = 0 ) = 0;
+	virtual INetworkStringTable	*CreateStringTable( const char *tableName, int maxentries, int userdatafixedsize = 0, int userdatanetworkbits = 0, int ) = 0;
 	virtual void				RemoveAllTables( void ) = 0;
 	
 	// table infos
@@ -73,8 +91,8 @@ public:
 	virtual INetworkStringTable	*GetTable( TABLEID stringTable ) const = 0;
 	virtual int					GetNumTables( void ) const = 0;
 
-	virtual INetworkStringTable	*CreateStringTableEx( const char *tableName, int maxentries, int userdatafixedsize = 0, int userdatanetworkbits = 0, bool bIsFilenames = false ) = 0;
 	virtual void				SetAllowClientSideAddString( INetworkStringTable *table, bool bAllowClientSideAddString ) = 0;
+	virtual INetworkStringDict	*CreateDictionary( const char *dictName ) = 0;
 };
 
 #endif // NETWORKSTRINGTABLEDEFS_H
diff --git a/public/tier1/convar.h b/public/tier1/convar.h
index ebeee2eb..34b10f91 100644
--- a/public/tier1/convar.h
+++ b/public/tier1/convar.h
@@ -120,6 +120,10 @@ public:
 	virtual bool				IsFlagSet( int flag ) const;
 	// Set flag
 	virtual void				AddFlags( int flags );
+	// Remove flag
+	virtual void				RemoveFlags( int flags );
+	// Get flags
+	virtual int					GetFlags( void ) const;
 
 	// Return name of cvar
 	virtual const char			*GetName( void ) const;
@@ -342,13 +346,14 @@ public:
 
 	virtual						~ConVar( void );
 
+	virtual	bool				IsCommand( void ) const;
 	virtual bool				IsFlagSet( int flag ) const;
+	virtual void				AddFlags( int flags );
+	virtual int					GetFlags( void ) const;
+	virtual const char			*GetName( void ) const;
 	virtual const char*			GetHelpText( void ) const;
 	virtual bool				IsRegistered( void ) const;
-	virtual const char			*GetName( void ) const;
-	virtual void				AddFlags( int flags );
-	virtual	bool				IsCommand( void ) const;
-
+		
 	// Install a change callback (there shouldn't already be one....)
 	void InstallChangeCallback( FnChangeCallback_t callback );
 
@@ -357,6 +362,12 @@ public:
 	FORCEINLINE_CVAR int			GetInt( void ) const;
 	FORCEINLINE_CVAR bool			GetBool() const {  return !!GetInt(); }
 	FORCEINLINE_CVAR char const	   *GetString( void ) const;
+	
+	// Used internally by OneTimeInit to initialize.
+	virtual void				Init();
+	
+	virtual const char 			*GetBaseName( void ) const;
+	virtual int					GetSplitScreenPlayerSlot ( void ) const;
 
 	// Any function that allocates/frees memory needs to be virtual or else you'll have crashes
 	//  from alloc/free across dll/exe boundaries.
@@ -388,9 +399,6 @@ private:
 									const char *pHelpString = 0, bool bMin = false, float fMin = 0.0,
 									bool bMax = false, float fMax = false, FnChangeCallback_t callback = 0 );
 
-	// Used internally by OneTimeInit to initialize.
-	virtual void				Init();
-
 private:
 
 	// This either points to "this" or it points to the original declaration of a ConVar.
diff --git a/public/tier1/iconvar.h b/public/tier1/iconvar.h
index 53a7e126..d673b027 100644
--- a/public/tier1/iconvar.h
+++ b/public/tier1/iconvar.h
@@ -104,10 +104,13 @@ public:
 
 	// Return name of command
 	virtual const char *GetName( void ) const = 0;
+	virtual const char *GetBaseName( void ) const = 0;
 
 	// Accessors.. not as efficient as using GetState()/GetInfo()
 	// if you call these methods multiple times on the same IConVar
 	virtual bool IsFlagSet( int nFlag ) const = 0;
+	
+	virtual int GetSplitScreenPlayerSlot( void ) const = 0;
 };
 
 
diff --git a/tier1/convar.cpp b/tier1/convar.cpp
index 5b693937..3a1b6696 100644
--- a/tier1/convar.cpp
+++ b/tier1/convar.cpp
@@ -241,6 +241,16 @@ void ConCommandBase::AddFlags( int flags )
 #endif
 }
 
+void ConCommandBase::RemoveFlags( int flags )
+{
+	m_nFlags &= ~flags;
+}
+
+int ConCommandBase::GetFlags( void ) const
+{
+	return m_nFlags;
+}
+
 
 //-----------------------------------------------------------------------------
 // Purpose: 
@@ -715,6 +725,11 @@ void ConVar::AddFlags( int flags )
 #endif
 }
 
+int ConVar::GetFlags( void ) const
+{
+	return m_pParent->m_nFlags;
+}
+
 bool ConVar::IsRegistered( void ) const
 {
 	return m_pParent->m_bRegistered;
@@ -743,6 +758,16 @@ void ConVar::Init()
 	BaseClass::Init();
 }
 
+const char *ConVar::GetBaseName( void ) const
+{
+	return m_pParent->m_pszName;
+}
+
+int ConVar::GetSplitScreenPlayerSlot( void ) const
+{
+	return 0;
+}
+
 //-----------------------------------------------------------------------------
 // Purpose: 
 // Input  : *value -