diff --git a/libraries/asmjit/asmjit/core/compiler.h b/libraries/asmjit/asmjit/core/compiler.h
index 293dcf2aa7..a59d2bc28b 100644
--- a/libraries/asmjit/asmjit/core/compiler.h
+++ b/libraries/asmjit/asmjit/core/compiler.h
@@ -327,7 +327,7 @@ public:
   FuncDetail _funcDetail;
   //! Function frame.
   FuncFrame _frame;
-  //! Function exit (label).
+  //! Function exit(label).
   LabelNode* _exitNode;
   //! Function end (sentinel).
   SentinelNode* _end;
diff --git a/libraries/glslang/spirv/SpvBuilder.h b/libraries/glslang/spirv/SpvBuilder.h
index edeac1b62b..f2773b55cf 100644
--- a/libraries/glslang/spirv/SpvBuilder.h
+++ b/libraries/glslang/spirv/SpvBuilder.h
@@ -493,7 +493,7 @@ public:
     // Add a branch to the continue_target of the current (innermost) loop.
     void createLoopContinue();
 
-    // Add an exit (e.g. "break") from the innermost loop that we're currently
+    // Add an exit(e.g. "break") from the innermost loop that we're currently
     // in.
     void createLoopExit();
 
diff --git a/src/console/c_cmds.cpp b/src/console/c_cmds.cpp
index a4e3ab5f8a..e99ff662c1 100644
--- a/src/console/c_cmds.cpp
+++ b/src/console/c_cmds.cpp
@@ -101,12 +101,12 @@ bool CheckCheatmode (bool printmsg)
 
 CCMD (quit)
 {
-	if (!insave) exit (0);
+	if (!insave) exit(0);
 }
 
 CCMD (exit)
 {
-	if (!insave) exit (0);
+	if (!insave) exit(0);
 }
 
 /*
diff --git a/src/d_net.cpp b/src/d_net.cpp
index 95e1cd7562..9bb00105ce 100644
--- a/src/d_net.cpp
+++ b/src/d_net.cpp
@@ -1604,7 +1604,7 @@ void D_ArbitrateNetStart (void)
 	StartScreen->NetInit ("Exchanging game information", 1);
 	if (!StartScreen->NetLoop (DoArbitrate, &data))
 	{
-		exit (0);
+		exit(0);
 	}
 
 	if (consoleplayer == Net_Arbitrator)
diff --git a/src/dobjtype.cpp b/src/dobjtype.cpp
index d7ea265bc9..fd430a352c 100644
--- a/src/dobjtype.cpp
+++ b/src/dobjtype.cpp
@@ -209,7 +209,7 @@ static int cregcmp (const void *a, const void *b) NO_SANITIZE
 
 void PClass::StaticInit ()
 {
-	atterm (StaticShutdown);
+	atterm(StaticShutdown);
 
 	Namespaces.GlobalNamespace = Namespaces.NewNamespace(0);
 
diff --git a/src/i_net.cpp b/src/i_net.cpp
index 717e204cfb..ca9b488f7f 100644
--- a/src/i_net.cpp
+++ b/src/i_net.cpp
@@ -435,7 +435,7 @@ void StartNetwork (bool autoPort)
 	}
 #endif
 
-	atterm (CloseNetwork);
+	atterm(CloseNetwork);
 
 	netgame = true;
 	multiplayer = true;
@@ -689,14 +689,14 @@ void HostGame (int i)
 
 	doomcom.numnodes = 1;
 
-	atterm (SendAbort);
+	atterm(SendAbort);
 
 	StartScreen->NetInit ("Waiting for players", numplayers);
 
 	// Wait for numplayers-1 different connections
 	if (!StartScreen->NetLoop (Host_CheckForConnects, (void *)(intptr_t)numplayers))
 	{
-		exit (0);
+		exit(0);
 	}
 
 	// Now inform everyone of all machines involved in the game
@@ -706,7 +706,7 @@ void HostGame (int i)
 
 	if (!StartScreen->NetLoop (Host_SendAllHere, (void *)gotack))
 	{
-		exit (0);
+		exit(0);
 	}
 
 	popterm ();
@@ -858,20 +858,20 @@ void JoinGame (int i)
 	sendplayer[1] = 0;
 	doomcom.numnodes = 2;
 
-	atterm (SendAbort);
+	atterm(SendAbort);
 
 	// Let host know we are here
 	StartScreen->NetInit ("Contacting host", 0);
 
 	if (!StartScreen->NetLoop (Guest_ContactHost, NULL))
 	{
-		exit (0);
+		exit(0);
 	}
 
 	// Wait for everyone else to connect
 	if (!StartScreen->NetLoop (Guest_WaitForOthers, 0))
 	{
-		exit (0);
+		exit(0);
 	}
 
 	popterm ();
diff --git a/src/m_misc.cpp b/src/m_misc.cpp
index ea69741538..aa4650ca93 100644
--- a/src/m_misc.cpp
+++ b/src/m_misc.cpp
@@ -320,7 +320,7 @@ void M_LoadDefaults ()
 {
 	GameConfig = new FGameConfigFile;
 	GameConfig->DoGlobalSetup ();
-	atterm (M_SaveDefaultsFinal);
+	atterm(M_SaveDefaultsFinal);
 }
 
 
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 5ee6ac5a3e..287c6d61a3 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -572,7 +572,7 @@ void P_SetupLevel(FLevelLocals *Level, int position, bool newGame)
 //
 void P_Init ()
 {
-	atterm (P_Shutdown);
+	atterm(P_Shutdown);
 
 	P_InitEffects ();		// [RH]
 	P_InitTerrainTypes ();
diff --git a/src/posix/cocoa/i_main.mm b/src/posix/cocoa/i_main.mm
index 73dd6ee2e6..489906a9d8 100644
--- a/src/posix/cocoa/i_main.mm
+++ b/src/posix/cocoa/i_main.mm
@@ -512,7 +512,7 @@ int main(int argc, char** argv)
 
 	CreateMenu();
 
-	atterm(ReleaseApplicationController);
+	atexit(ReleaseApplicationController);
 
 	appCtrl = [ApplicationController new];
 	[NSApp setDelegate:appCtrl];
diff --git a/src/posix/sdl/hardware.cpp b/src/posix/sdl/hardware.cpp
index eb71e6e97b..b761529afd 100644
--- a/src/posix/sdl/hardware.cpp
+++ b/src/posix/sdl/hardware.cpp
@@ -84,5 +84,5 @@ void I_InitGraphics ()
 	if (Video == NULL)
 		I_FatalError ("Failed to initialize display");
 
-	atterm (I_ShutdownGraphics);
+	atterm(I_ShutdownGraphics);
 }
diff --git a/src/posix/sdl/i_input.cpp b/src/posix/sdl/i_input.cpp
index 18d8af0a2d..040abe736e 100644
--- a/src/posix/sdl/i_input.cpp
+++ b/src/posix/sdl/i_input.cpp
@@ -297,7 +297,7 @@ void MessagePump (const SDL_Event &sev)
 	switch (sev.type)
 	{
 	case SDL_QUIT:
-		exit (0);
+		exit(0);
 
 	case SDL_WINDOWEVENT:
 		extern void ProcessSDLWindowEvent(const SDL_WindowEvent &);
diff --git a/src/posix/sdl/i_main.cpp b/src/posix/sdl/i_main.cpp
index 34d2d070e9..e454f775f6 100644
--- a/src/posix/sdl/i_main.cpp
+++ b/src/posix/sdl/i_main.cpp
@@ -241,7 +241,7 @@ int main (int argc, char **argv)
 			}
 		}
 
-		exit (-1);
+		return -1;
     }
     catch (...)
     {
diff --git a/src/posix/sdl/i_system.cpp b/src/posix/sdl/i_system.cpp
index faf9576015..dd89c7bcef 100644
--- a/src/posix/sdl/i_system.cpp
+++ b/src/posix/sdl/i_system.cpp
@@ -98,7 +98,7 @@ void I_Init (void)
 	CheckCPUID (&CPU);
 	DumpCPUInfo (&CPU);
 
-	atterm (I_ShutdownSound);
+	atterm(I_ShutdownSound);
 	I_InitSound ();
 }
 
@@ -171,7 +171,7 @@ void I_FatalError (const char *error, va_list ap)
 		}
 //		throw CFatalError (errortext);
 		fprintf (stderr, "%s\n", errortext);
-		exit (-1);
+		exit(-1);
 	}
 	std::terminate();
 }
diff --git a/src/rendering/r_utility.cpp b/src/rendering/r_utility.cpp
index 6e063928c4..4258b6278d 100644
--- a/src/rendering/r_utility.cpp
+++ b/src/rendering/r_utility.cpp
@@ -380,7 +380,7 @@ FRenderer *CreateSWRenderer();
 
 void R_Init ()
 {
-	atterm (R_Shutdown);
+	atterm(R_Shutdown);
 
 	StartScreen->Progress();
 	R_InitTranslationTables ();
diff --git a/src/rendering/v_video.cpp b/src/rendering/v_video.cpp
index 51f2d83e1c..bcda5920d0 100644
--- a/src/rendering/v_video.cpp
+++ b/src/rendering/v_video.cpp
@@ -563,7 +563,7 @@ void V_InitScreenSize ()
 	const char *i;
 	int width, height, bits;
 	
-	atterm (V_Shutdown);
+	atterm(V_Shutdown);
 	
 	
 	width = height = bits = 0;
diff --git a/src/sound/s_advsound.cpp b/src/sound/s_advsound.cpp
index 42194d57d7..c0bf79b09d 100644
--- a/src/sound/s_advsound.cpp
+++ b/src/sound/s_advsound.cpp
@@ -986,7 +986,7 @@ void S_ParseSndInfo (bool redefine)
 	int lump;
 
 	if (!redefine) SavedPlayerSounds.Clear();	// clear skin sounds only for initial parsing.
-	atterm (S_ClearSoundData);
+	atterm(S_ClearSoundData);
 	S_ClearSoundData();	// remove old sound data first!
 
 	CurrentPitchMask = 0;
diff --git a/src/sound/s_environment.cpp b/src/sound/s_environment.cpp
index cfc9e87b89..64bb93bd7a 100644
--- a/src/sound/s_environment.cpp
+++ b/src/sound/s_environment.cpp
@@ -643,7 +643,7 @@ void S_ParseReverbDef ()
 {
 	int lump, lastlump = 0;
 
-	atterm (S_UnloadReverbDef);
+	atterm(S_UnloadReverbDef);
 	S_UnloadReverbDef ();
 
 	while ((lump = Wads.FindLump ("REVERBS", &lastlump)) != -1)
diff --git a/src/sound/s_sound.cpp b/src/sound/s_sound.cpp
index 7242bb8c57..7820f1cce0 100644
--- a/src/sound/s_sound.cpp
+++ b/src/sound/s_sound.cpp
@@ -305,7 +305,7 @@ void S_Init ()
 {
 	int curvelump;
 
-	atterm (S_Shutdown);
+	atterm(S_Shutdown);
 
 	// Heretic and Hexen have sound curve lookup tables. Doom does not.
 	curvelump = Wads.CheckNumForName ("SNDCURVE");
diff --git a/src/win32/hardware.cpp b/src/win32/hardware.cpp
index 98af9957c8..c015c3a7af 100644
--- a/src/win32/hardware.cpp
+++ b/src/win32/hardware.cpp
@@ -152,5 +152,5 @@ void I_InitGraphics ()
 	if (Video == NULL)
 		I_FatalError ("Failed to initialize display");
 	
-	atterm (I_ShutdownGraphics);
+	atterm(I_ShutdownGraphics);
 }
diff --git a/src/win32/i_input.cpp b/src/win32/i_input.cpp
index 3c251d1472..3846884eae 100644
--- a/src/win32/i_input.cpp
+++ b/src/win32/i_input.cpp
@@ -424,7 +424,7 @@ LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
 	case WM_DESTROY:
 		SetPriorityClass (GetCurrentProcess(), NORMAL_PRIORITY_CLASS);
 		//PostQuitMessage (0);
-		exit (0);
+		exit(0);
 		break;
 
 	case WM_HOTKEY:
@@ -614,7 +614,7 @@ bool I_InitInput (void *hwnd)
 	HRESULT hr;
 
 	Printf ("I_InitInput\n");
-	atterm (I_ShutdownInput);
+	atterm(I_ShutdownInput);
 
 	noidle = !!Args->CheckParm ("-noidle");
 	g_pdi = NULL;
@@ -740,7 +740,7 @@ void I_GetEvent ()
 	while (PeekMessage (&mess, NULL, 0, 0, PM_REMOVE))
 	{
 		if (mess.message == WM_QUIT)
-			exit (mess.wParam);
+			exit(mess.wParam);
 
 		if (GUICapture)
 		{
diff --git a/src/win32/i_main.cpp b/src/win32/i_main.cpp
index fdf2f51f9a..9119a9c78a 100644
--- a/src/win32/i_main.cpp
+++ b/src/win32/i_main.cpp
@@ -932,7 +932,7 @@ void DoMain (HINSTANCE hInstance)
 
 		if (!Window)
 		{
-			MessageBoc(nullptr, "Fatal", "Unable to create main window", MB_ICONEXCLAMATION|MB_OK);
+			MessageBoxA(nullptr, "Unable to create main window", "Fatal", MB_ICONEXCLAMATION|MB_OK);
 			exit(-1);
 		}
 
@@ -1019,7 +1019,7 @@ void DoMain (HINSTANCE hInstance)
 				Printf("%s\n", msg);
 			}
 		}
-		exit (-1);
+		exit(-1);
 	}
 }
 
@@ -1133,7 +1133,7 @@ void CALLBACK ExitFatally (ULONG_PTR dummy)
 	I_ShutdownGraphics ();
 	RestoreConView ();
 	DisplayCrashLog ();
-	exit (-1);
+	exit(-1);
 }
 
 //==========================================================================
@@ -1233,7 +1233,7 @@ int WINAPI wWinMain (HINSTANCE hInstance, HINSTANCE nothing, LPWSTR cmdline, int
 		// don't support Windows 95, we have no obligation to provide assistance in
 		// getting it installed.
 		MessageBoxA(NULL, "Could not load riched20.dll", GAMENAME " Error", MB_OK | MB_ICONSTOP);
-		exit(0);
+		return 0;
 	}
 
 #if !defined(__GNUC__) && defined(_DEBUG)
@@ -1248,7 +1248,7 @@ int WINAPI wWinMain (HINSTANCE hInstance, HINSTANCE nothing, LPWSTR cmdline, int
 		{
 		}
 		DisplayCrashLog ();
-		exit (0);
+		return 0;
 	}
 	if (__argc == 2 && __wargv != nullptr && wcscmp (__wargv[1], L"TestStackCrash") == 0)
 	{
@@ -1261,7 +1261,7 @@ int WINAPI wWinMain (HINSTANCE hInstance, HINSTANCE nothing, LPWSTR cmdline, int
 		{
 		}
 		DisplayCrashLog ();
-		exit (0);
+		return 0;
 	}
 #endif
 
diff --git a/src/win32/i_system.cpp b/src/win32/i_system.cpp
index 9fdf14dd00..8d52903e62 100644
--- a/src/win32/i_system.cpp
+++ b/src/win32/i_system.cpp
@@ -337,7 +337,7 @@ void I_Init()
 	CalculateCPUSpeed();
 	DumpCPUInfo(&CPU);
 
-	atterm (I_ShutdownSound);
+	atterm(I_ShutdownSound);
 	I_InitSound ();
 }
 
diff --git a/src/win32/st_start.cpp b/src/win32/st_start.cpp
index 72daf79ac8..420618ec67 100644
--- a/src/win32/st_start.cpp
+++ b/src/win32/st_start.cpp
@@ -1343,13 +1343,11 @@ void FStrifeStartupScreen::DrawStuff(int old_laser, int new_laser)
 //
 //==========================================================================
 
-void ST_Endoom()
+int RunEndoom()
 {
-	if (showendoom == 0) exit(0);
-
-	if (gameinfo.Endoom.Len() == 0) 
+	if (showendoom == 0 || gameinfo.Endoom.Len() == 0) 
 	{
-		exit(0);
+		return 0;
 	}
 
 	int endoom_lump = Wads.CheckNumForFullName (gameinfo.Endoom, true);
@@ -1363,25 +1361,25 @@ void ST_Endoom()
 
 	if (endoom_lump < 0 || Wads.LumpLength (endoom_lump) != 4000)
 	{
-		exit(0);
+		return 0;
 	}
 
 	if (Wads.GetLumpFile(endoom_lump) == Wads.GetMaxIwadNum() && showendoom == 2)
 	{
 		// showendoom==2 means to show only lumps from PWADs.
-		exit(0);
+		return 0;
 	}
 
 	font = ST_Util_LoadFont (TEXT_FONT_NAME);
 	if (font == NULL)
 	{
-		exit(0);
+		return 0;
 	}
 
 	if (!ST_Util_CreateStartupWindow())
 	{
 		ST_Util_FreeFont (font);
-		exit(0);
+		return 0;
 	}
 
 	I_ShutdownGraphics ();
@@ -1432,7 +1430,7 @@ void ST_Endoom()
 			}
 			ST_Util_FreeBitmap (StartupBitmap);
 			ST_Util_FreeFont (font);
-			exit (int(bRet == 0 ? mess.wParam : 0));
+			return int(bRet == 0 ? mess.wParam : 0);
 		}
 		else if (blinking && mess.message == WM_TIMER && mess.hwnd == Window && mess.wParam == 0x5A15A)
 		{
@@ -1444,6 +1442,13 @@ void ST_Endoom()
 	}
 }
 
+void ST_Endoom()
+{
+	int code = RunEndoom();
+	exit(code);
+
+}
+
 //==========================================================================
 //
 // ST_Util_CreateStartupWindow
diff --git a/tools/re2c/src/ir/skeleton/generate_data.cc b/tools/re2c/src/ir/skeleton/generate_data.cc
index 60af8376eb..2fb8a607bf 100644
--- a/tools/re2c/src/ir/skeleton/generate_data.cc
+++ b/tools/re2c/src/ir/skeleton/generate_data.cc
@@ -131,14 +131,14 @@ void Skeleton::emit_data (const char * fname)
 	if (!input)
 	{
 		error ("cannot open file: %s", input_name.c_str ());
-		exit (1);
+		exit(1);
 	}
 	const std::string keys_name = std::string (fname) + "." + name + ".keys";
 	FILE * keys = fopen (keys_name.c_str (), "wb");
 	if (!keys)
 	{
 		error ("cannot open file: %s", keys_name.c_str ());
-		exit (1);
+		exit(1);
 	}
 
 	generate_paths (input, keys);
diff --git a/tools/re2c/src/ir/skeleton/skeleton.cc b/tools/re2c/src/ir/skeleton/skeleton.cc
index deee113340..6838f17f25 100644
--- a/tools/re2c/src/ir/skeleton/skeleton.cc
+++ b/tools/re2c/src/ir/skeleton/skeleton.cc
@@ -116,7 +116,7 @@ Skeleton::Skeleton
 	if (maxlen == Node::DIST_MAX)
 	{
 		error ("DFA path %sis too long", incond (cond).c_str ());
-		exit (1);
+		exit(1);
 	}
 
 	// calculate maximal rule rank (disregarding default and none rules)