diff --git a/BizHawk.MultiClient/Config.cs b/BizHawk.MultiClient/Config.cs
index 7620863f55..905af9deb3 100644
--- a/BizHawk.MultiClient/Config.cs
+++ b/BizHawk.MultiClient/Config.cs
@@ -153,6 +153,7 @@ namespace BizHawk.MultiClient
 		public bool AutoLoadLastSaveSlot = false;
 		public bool WIN32_CONSOLE = true;
 		public bool SkipLagFrame = false;
+		public string MovieExtension = "bkm";
 
 		// Run-Control settings
 		public int FrameProgressDelayMs = 500; //how long until a frame advance hold turns into a frame progress?
diff --git a/BizHawk.MultiClient/MainForm.cs b/BizHawk.MultiClient/MainForm.cs
index eabd9789ac..39e145cff6 100644
--- a/BizHawk.MultiClient/MainForm.cs
+++ b/BizHawk.MultiClient/MainForm.cs
@@ -885,7 +885,7 @@ namespace BizHawk.MultiClient
 				case "GB": str += "gb"; break;
 			}
 
-			return str + ".tas";
+			return str + "." + Global.Config.MovieExtension;
 		}
 
 		private void HandlePlatformMenus()
@@ -2732,7 +2732,7 @@ namespace BizHawk.MultiClient
 				if (warningMsg.Length > 0)
 					Global.RenderPanel.AddMessage(warningMsg);
 				else
-					Global.RenderPanel.AddMessage(Path.GetFileName(fn) + " imported as .tas");
+					Global.RenderPanel.AddMessage(Path.GetFileName(fn) + " imported as ." + Global.Config.MovieExtension);
 			}
 		}
 
diff --git a/BizHawk.MultiClient/PlayMovie.cs b/BizHawk.MultiClient/PlayMovie.cs
index 197d68855c..1e18b18de7 100644
--- a/BizHawk.MultiClient/PlayMovie.cs
+++ b/BizHawk.MultiClient/PlayMovie.cs
@@ -72,8 +72,7 @@ namespace BizHawk.MultiClient
 		{
 			OpenFileDialog ofd = new OpenFileDialog();
 			ofd.InitialDirectory = PathManager.MakeAbsolutePath(Global.Config.MoviesPath, "");
-            ofd.Filter = "Generic Movie Files (*.tas)|*.tas;*.zip;*.7z|" + Global.MainForm.GetMovieExtName() + "|Savestates|*.state|Archive Files|*.zip;*.7z|All Files|*.*";
-            //ofd.Filter = "Generic Movie Files (*.tas)|*.tas;*.zip;*.7z|Savestates|*.state|Archive Files|*.zip;*.7z|All Files|*.*";
+			ofd.Filter = "Generic Movie Files (*." + Global.Config.MovieExtension + ")|*." + Global.Config.MovieExtension + ";*.zip;*.7z|" + Global.MainForm.GetMovieExtName() + "|Savestates|*.state|Archive Files|*.zip;*.7z|All Files|*.*";
 
 			Global.Sound.StopSound();
 			var result = ofd.ShowDialog();
@@ -269,7 +268,7 @@ namespace BizHawk.MultiClient
 			if (!Directory.Exists(d))
 				Directory.CreateDirectory(d);
 
-			foreach (string f in Directory.GetFiles(d, "*.tas"))
+			foreach (string f in Directory.GetFiles(d, "*." + Global.Config.MovieExtension))
 				AddMovieToList(f);
 			if (Global.Config.PlayMovie_ShowStateFiles)
 			{
@@ -282,7 +281,7 @@ namespace BizHawk.MultiClient
 				string[] subs = Directory.GetDirectories(d);
 				foreach (string dir in subs)
 				{
-					foreach (string f in Directory.GetFiles(dir, "*.tas"))
+					foreach (string f in Directory.GetFiles(dir, "*." + Global.Config.MovieExtension))
 						AddMovieToList(f);
 					if (Global.Config.PlayMovie_ShowStateFiles)
 					{
@@ -370,7 +369,7 @@ namespace BizHawk.MultiClient
 			string[] filePaths = (string[])e.Data.GetData(DataFormats.FileDrop);
 			foreach (string path in filePaths)
 			{
-				if (Path.GetExtension(path) == ".tas")
+				if (Path.GetExtension(path) == "." + Global.Config.MovieExtension)
 					AddMovieToList(path);
 			}
 		}
diff --git a/BizHawk.MultiClient/RecordMovie.cs b/BizHawk.MultiClient/RecordMovie.cs
index 9d637b3a63..49d2e0f4ba 100644
--- a/BizHawk.MultiClient/RecordMovie.cs
+++ b/BizHawk.MultiClient/RecordMovie.cs
@@ -36,8 +36,8 @@ namespace BizHawk.MultiClient
 					path = path.Insert(0, "\\");
 				path = PathManager.MakeAbsolutePath(Global.Config.MoviesPath, "") + path;
 
-				if (path[path.Length - 4] != '.') //If no file extension, add .tas
-					path += ".tas";
+				if (path[path.Length - 4] != '.') //If no file extension, add movie extension
+					path += "." + Global.Config.MovieExtension;
 				return path;
 			}
 			else
@@ -118,10 +118,9 @@ namespace BizHawk.MultiClient
 		{
 			SaveFileDialog sfd = new SaveFileDialog();
 			sfd.InitialDirectory = PathManager.MakeAbsolutePath(Global.Config.MoviesPath, "");
-			sfd.DefaultExt = ".tas";
+			sfd.DefaultExt = "." + Global.Config.MovieExtension;
 			sfd.FileName = PathManager.FilesystemSafeName(Global.Game) + "." + sfd.DefaultExt;
-			sfd.Filter = "Generic Movie Files (*.tas)|*.tas|" + Global.MainForm.GetMovieExtName() + "|All Files (*.*)|*.*";
-            //sfd.Filter = "Generic Movie Files (*.tas)|*.tas|All Files (*.*)|*.*";
+			sfd.Filter = "Generic Movie Files (*." + Global.Config.MovieExtension + ")|*." + Global.Config.MovieExtension +  "|" + Global.MainForm.GetMovieExtName() + "|All Files (*.*)|*.*";
 
 			Global.Sound.StopSound();
 			var result = sfd.ShowDialog();
diff --git a/BizHawk.MultiClient/movie/MovieImport.cs b/BizHawk.MultiClient/movie/MovieImport.cs
index 7e557e6daa..be23b891c4 100644
--- a/BizHawk.MultiClient/movie/MovieImport.cs
+++ b/BizHawk.MultiClient/movie/MovieImport.cs
@@ -90,7 +90,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileInfo file = new FileInfo(path);
 			StreamReader sr = file.OpenText();
 			string[] buttons = new string[] { };
@@ -307,7 +307,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 4-byte signature: 46 43 4D 1A "FCM\x1A"
@@ -562,7 +562,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 4-byte signature: 46 4D 56 1A "FMV\x1A"
@@ -692,7 +692,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 16-byte signature and format version: "Gens Movie TEST9"
@@ -806,7 +806,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 8-byte    "MDFNMOVI" signature
@@ -929,7 +929,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 0000: 4-byte signature: "MMV\0"
@@ -1044,7 +1044,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 4-byte signature: 4E 53 53 1A "NSS\x1A"
@@ -1293,7 +1293,7 @@ namespace BizHawk.MultiClient
 		// SMV 1.43 file format: http://code.google.com/p/snes9x-rr/wiki/SMV143
 		private static Movie ImportSMV143(BinaryReader r, string path)
 		{
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			uint GUID = r.ReadUInt32();
 			m.Header.SetHeaderLine(MovieHeader.GUID, GUID.ToString()); //TODO: format to hex string
 			m.SetRerecords((int)r.ReadUInt32());
@@ -1348,7 +1348,7 @@ namespace BizHawk.MultiClient
 		// SMV 1.51 file format: http://code.google.com/p/snes9x-rr/wiki/SMV151
 		private static Movie ImportSMV151(BinaryReader r, string path)
 		{
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			m.Header.Comments.Add(EMULATIONORIGIN + " Snes9x version 1.51");
 			m.Header.Comments.Add(MOVIEORIGIN + " .SMV");
 			return m;
@@ -1356,7 +1356,7 @@ namespace BizHawk.MultiClient
 
 		private static Movie ImportSMV152(BinaryReader r, string path)
 		{
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			uint GUID = r.ReadUInt32();
 			m.Header.Comments.Add(EMULATIONORIGIN + " Snes9x version 1.52");
 			m.Header.Comments.Add(MOVIEORIGIN + " .SMV");
@@ -1368,7 +1368,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 4-byte signature: 56 42 4D 1A "VBM\x1A"
@@ -1594,7 +1594,7 @@ namespace BizHawk.MultiClient
 		{
 			errorMsg = "";
 			warningMsg = "";
-			Movie m = new Movie(path + ".tas", MOVIEMODE.PLAY);
+			Movie m = new Movie(path + "." + Global.Config.MovieExtension, MOVIEMODE.PLAY);
 			FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
 			BinaryReader r = new BinaryReader(fs);
 			// 000 12-byte signature: "VirtuaNES MV"
diff --git a/BizHawk.MultiClient/tools/TAStudio.cs b/BizHawk.MultiClient/tools/TAStudio.cs
index 9d9856ff23..c439872b41 100644
--- a/BizHawk.MultiClient/tools/TAStudio.cs
+++ b/BizHawk.MultiClient/tools/TAStudio.cs
@@ -32,7 +32,7 @@ namespace BizHawk.MultiClient
 
 		//Movie header object - to have the main project header data
 		//List<string> MacroFiles - list of .macro files (simply log files)
-		//List<string> TimeLines - list of .tas files
+		//List<string> TimeLines - list of movie files
 		//List<string> Bookmarks - list of savestate files
 
 		public TAStudio()