diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
index 2eab4970..17380db7 100644
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@@ -17,6 +17,7 @@ jobs:
           --style=file \
           ISLE/*.cpp ISLE/*.h \
           LEGO1/*.cpp LEGO1/*.h \
+          LEGO1/mxstl/*.h \
           LEGO1/realtime/*.cpp LEGO1/realtime/*.h \
           LEGO1/tgl/*.h \
           LEGO1/tgl/d3drm/*.cpp LEGO1/tgl/d3drm/*.h \
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a60e3d4..ed3c29cf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -230,6 +230,8 @@ if (MINGW)
 endif()
 
 # Additional include directories
+
+target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/util")
 target_include_directories(lego1 PUBLIC "${CMAKE_SOURCE_DIR}/3rdparty/vec")
 target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/3rdparty/flic")
 target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/3rdparty/smk")
@@ -264,6 +266,8 @@ if (ISLE_BUILD_APP)
     ISLE/define.cpp
   )
 
+  target_include_directories(isle PRIVATE "${CMAKE_SOURCE_DIR}/util")
+
   # Include LEGO1 headers in ISLE
   target_include_directories(isle PRIVATE "${CMAKE_SOURCE_DIR}/LEGO1")
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1a698a7d..0c65bc1c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -27,6 +27,7 @@ This repository currently has only one goal: accuracy to the original executable
 * [`ISLE`](/ISLE): Decompilation of `ISLE.EXE`. It depends on some code in `LEGO1`.
 * [`LEGO1`](/LEGO1): Decompilation of `LEGO1.DLL`. This folder contains code from Mindscape's custom in-house engine called **Omni** (file pattern: `mx*`), the LEGO Island-specific extensions for Omni and the game's code (file pattern: `lego*`) as well as several utility libraries developed by Mindscape.
 * [`tools`](/tools): A set of tools aiding in the decompilation effort.
+* [`util`](/util): Utility headers aiding in the decompilation effort.
 
 ## Tooling
 
diff --git a/LEGO1/mxatomidcounter.h b/LEGO1/mxatomidcounter.h
index c75c2b5c..8fb5ae97 100644
--- a/LEGO1/mxatomidcounter.h
+++ b/LEGO1/mxatomidcounter.h
@@ -1,7 +1,7 @@
 #ifndef MXATOMIDCOUNTER_H
 #define MXATOMIDCOUNTER_H
 
-#include "compat.h" // STL
+#include "mxstl/stlcompat.h"
 #include "mxstring.h"
 
 // Counts the number of existing MxAtomId objects based
diff --git a/LEGO1/mxbackgroundaudiomanager.cpp b/LEGO1/mxbackgroundaudiomanager.cpp
index 36f9faa8..b89b5cf4 100644
--- a/LEGO1/mxbackgroundaudiomanager.cpp
+++ b/LEGO1/mxbackgroundaudiomanager.cpp
@@ -244,7 +244,7 @@ MxResult MxBackgroundAudioManager::PlayMusic(MxDSAction& p_action, undefined4 p_
 		m_action2.SetAtomId(p_action.GetAtomId());
 		m_action2.SetObjectId(p_action.GetObjectId());
 		m_action2.SetUnknown84(this);
-		m_action2.SetUnknown8c(this);
+		m_action2.SetOrigin(this);
 
 		MxResult result = Start(&m_action2);
 
diff --git a/LEGO1/mxcompositepresenter.cpp b/LEGO1/mxcompositepresenter.cpp
index 8c549c88..087dab7d 100644
--- a/LEGO1/mxcompositepresenter.cpp
+++ b/LEGO1/mxcompositepresenter.cpp
@@ -1,7 +1,11 @@
 #include "mxcompositepresenter.h"
 
 #include "decomp.h"
+#include "mxactionnotificationparam.h"
+#include "mxautolocker.h"
+#include "mxdsmultiaction.h"
 #include "mxnotificationmanager.h"
+#include "mxobjectfactory.h"
 
 DECOMP_SIZE_ASSERT(MxCompositePresenter, 0x4c);
 
@@ -13,6 +17,9 @@ MxBool MxCompositePresenter::VTable0x64(undefined4 p_unknown)
 	return TRUE;
 }
 
+// TEMPLATE: LEGO1 0x1004ae90
+// list<MxPresenter *,allocator<MxPresenter *> >::_Buynode
+
 // FUNCTION: LEGO1 0x100b60b0
 MxCompositePresenter::MxCompositePresenter()
 {
@@ -25,34 +32,106 @@ MxCompositePresenter::~MxCompositePresenter()
 	NotificationManager()->Unregister(this);
 }
 
-// STUB: LEGO1 0x100b6410
-MxResult MxCompositePresenter::StartAction(MxStreamController*, MxDSAction*)
+// FUNCTION: LEGO1 0x100b6410
+MxResult MxCompositePresenter::StartAction(MxStreamController* p_controller, MxDSAction* p_action)
 {
-	// TODO
-	return SUCCESS;
+	MxAutoLocker lock(&m_criticalSection);
+
+	MxResult result = FAILURE;
+	MxDSActionList* actions = ((MxDSMultiAction*) p_action)->GetActionList();
+	MxObjectFactory* factory = ObjectFactory();
+	MxDSActionListCursor cursor(actions);
+	MxDSAction* action;
+
+	if (MxPresenter::StartAction(p_controller, p_action) == SUCCESS) {
+		// The usual cursor.Next() loop doesn't match here, even though
+		// the logic is the same. It does match when "deconstructed" into
+		// the following Head(), Current() and NextFragment() calls,
+		// but this seems unlikely to be the original code.
+		// The alpha debug build also uses Next().
+		cursor.Head();
+		while (cursor.Current(action)) {
+			cursor.NextFragment();
+
+			MxBool success = FALSE;
+
+			action->CopyFlags(m_action->GetFlags());
+
+			const char* presenterName = PresenterNameDispatch(*action);
+			MxPresenter* presenter = (MxPresenter*) factory->Create(presenterName);
+
+			if (presenter && presenter->AddToManager() == SUCCESS) {
+				presenter->SetCompositePresenter(this);
+				if (presenter->StartAction(p_controller, action) == SUCCESS)
+					success = TRUE;
+			}
+
+			if (success) {
+				action->SetOrigin(this);
+				m_list.push_back(presenter);
+			}
+			else if (presenter)
+				delete presenter;
+		}
+
+		result = SUCCESS;
+	}
+
+	return result;
 }
 
-// STUB: LEGO1 0x100b65e0
+// FUNCTION: LEGO1 0x100b65e0
 void MxCompositePresenter::EndAction()
 {
-	// TODO
+	MxAutoLocker lock(&m_criticalSection);
+
+	if (!m_action)
+		return;
+
+	((MxDSMultiAction*) m_action)->GetActionList()->DeleteAll(FALSE);
+
+	while (!m_list.empty()) {
+		MxPresenter* presenter = m_list.front();
+		m_list.pop_front();
+		presenter->SetCompositePresenter(NULL);
+		presenter->EndAction();
+	}
+
+	MxDSAction* action = m_action;
+	MxPresenter::EndAction();
+
+	if (action && action->GetOrigin()) {
+		NotificationManager()->Send(
+			action->GetOrigin(),
+			&MxEndActionNotificationParam(c_notificationEndAction, this, action, FALSE)
+		);
+	}
 }
 
-// STUB: LEGO1 0x100b6760
+// FUNCTION: LEGO1 0x100b6760
 MxLong MxCompositePresenter::Notify(MxParam& p)
 {
-	// TODO
+	MxAutoLocker lock(&m_criticalSection);
+
+	switch (((MxNotificationParam&) p).GetNotification()) {
+	case c_notificationEndAction:
+		VTable0x58(p);
+		break;
+	case MXPRESENTER_NOTIFICATION:
+		VTable0x5c(p);
+	}
+
 	return 0;
 }
 
 // STUB: LEGO1 0x100b67f0
-void MxCompositePresenter::VTable0x58()
+void MxCompositePresenter::VTable0x58(MxParam& p)
 {
 	// TODO
 }
 
 // STUB: LEGO1 0x100b69b0
-void MxCompositePresenter::VTable0x5c()
+void MxCompositePresenter::VTable0x5c(MxParam& p)
 {
 	// TODO
 }
diff --git a/LEGO1/mxcompositepresenter.h b/LEGO1/mxcompositepresenter.h
index 64a0b236..68e9846d 100644
--- a/LEGO1/mxcompositepresenter.h
+++ b/LEGO1/mxcompositepresenter.h
@@ -1,8 +1,8 @@
 #ifndef MXCOMPOSITEPRESENTER_H
 #define MXCOMPOSITEPRESENTER_H
 
-#include "compat.h" // STL
 #include "mxpresenter.h"
+#include "mxstl/stlcompat.h"
 
 class MxCompositePresenterList : public list<MxPresenter*> {};
 
@@ -28,15 +28,15 @@ class MxCompositePresenter : public MxPresenter {
 		return !strcmp(name, MxCompositePresenter::ClassName()) || MxPresenter::IsA(name);
 	}
 
-	virtual MxResult StartAction(MxStreamController*, MxDSAction*) override; // vtable+0x3c
-	virtual void EndAction() override;                                       // vtable+0x40
-	virtual void SetTickleState(TickleState p_tickleState) override;         // vtable+0x44
-	virtual MxBool HasTickleStatePassed(TickleState p_tickleState) override; // vtable+0x48
-	virtual void Enable(MxBool p_enable) override;                           // vtable+0x54
-	virtual void VTable0x58();                                               // vtable+0x58
-	virtual void VTable0x5c();                                               // vtable+0x5c
-	virtual void VTable0x60(MxPresenter* p_presenter);                       // vtable+0x60
-	virtual MxBool VTable0x64(undefined4 p_unknown);                         // vtable+0x64
+	virtual MxResult StartAction(MxStreamController*, MxDSAction* p_action) override; // vtable+0x3c
+	virtual void EndAction() override;                                                // vtable+0x40
+	virtual void SetTickleState(TickleState p_tickleState) override;                  // vtable+0x44
+	virtual MxBool HasTickleStatePassed(TickleState p_tickleState) override;          // vtable+0x48
+	virtual void Enable(MxBool p_enable) override;                                    // vtable+0x54
+	virtual void VTable0x58(MxParam& p);                                              // vtable+0x58
+	virtual void VTable0x5c(MxParam& p);                                              // vtable+0x5c
+	virtual void VTable0x60(MxPresenter* p_presenter);                                // vtable+0x60
+	virtual MxBool VTable0x64(undefined4 p_unknown);                                  // vtable+0x64
 
 private:
 	MxCompositePresenterList m_list; // 0x40
diff --git a/LEGO1/mxdiskstreamcontroller.h b/LEGO1/mxdiskstreamcontroller.h
index aadb9036..fc9b7d7e 100644
--- a/LEGO1/mxdiskstreamcontroller.h
+++ b/LEGO1/mxdiskstreamcontroller.h
@@ -1,9 +1,9 @@
 #ifndef MXDISKSTREAMCONTROLLER_H
 #define MXDISKSTREAMCONTROLLER_H
 
-#include "compat.h" // STL
 #include "decomp.h"
 #include "mxdsbuffer.h"
+#include "mxstl/stlcompat.h"
 #include "mxstreamcontroller.h"
 #include "mxtypes.h"
 
diff --git a/LEGO1/mxdsaction.cpp b/LEGO1/mxdsaction.cpp
index 7d2f6645..a01bceff 100644
--- a/LEGO1/mxdsaction.cpp
+++ b/LEGO1/mxdsaction.cpp
@@ -28,7 +28,7 @@ MxDSAction::MxDSAction()
 	this->m_up.Fill(FLT_MAX);
 	this->m_unk84 = NULL;
 	this->m_unk88 = 0;
-	this->m_unk8c = NULL;
+	this->m_origin = NULL;
 	this->m_unkTimingField = INT_MIN;
 }
 
@@ -84,7 +84,7 @@ void MxDSAction::CopyFrom(MxDSAction& p_dsAction)
 	AppendData(p_dsAction.m_extraLength, p_dsAction.m_extraData);
 	this->m_unk84 = p_dsAction.m_unk84;
 	this->m_unk88 = p_dsAction.m_unk88;
-	this->m_unk8c = p_dsAction.m_unk8c;
+	this->m_origin = p_dsAction.m_origin;
 	this->m_unkTimingField = p_dsAction.m_unkTimingField;
 }
 
diff --git a/LEGO1/mxdsaction.h b/LEGO1/mxdsaction.h
index e3c6f171..9047c730 100644
--- a/LEGO1/mxdsaction.h
+++ b/LEGO1/mxdsaction.h
@@ -64,12 +64,20 @@ class MxDSAction : public MxDSObject {
 	inline void SetLoopCount(MxS32 p_loopCount) { m_loopCount = p_loopCount; }
 	inline const Vector3Data& GetLocation() const { return m_location; }
 	inline void SetUnknown84(MxCore* p_unk84) { m_unk84 = p_unk84; }
-	inline MxCore* GetUnknown8c() { return m_unk8c; }
-	inline void SetUnknown8c(MxCore* p_unk8c) { m_unk8c = p_unk8c; }
+	inline MxCore* GetOrigin() { return m_origin; }
+	inline void SetOrigin(MxCore* p_origin) { m_origin = p_origin; }
 
 	inline MxBool IsLooping() const { return m_flags & Flag_Looping; }
 	inline MxBool IsBit3() const { return m_flags & Flag_Bit3; }
 
+	inline void CopyFlags(MxU32 p_flags)
+	{
+		if (p_flags & MxDSAction::Flag_Looping)
+			SetFlags(GetFlags() | MxDSAction::Flag_Looping);
+		else if (p_flags & MxDSAction::Flag_Bit3)
+			SetFlags(GetFlags() | MxDSAction::Flag_Bit3);
+	}
+
 protected:
 	MxU32 m_sizeOnDisk;      // 0x2c
 	MxU32 m_flags;           // 0x30
@@ -83,7 +91,7 @@ class MxDSAction : public MxDSObject {
 	MxU16 m_extraLength;     // 0x80
 	MxCore* m_unk84;         // 0x84
 	undefined4 m_unk88;      // 0x88
-	MxCore* m_unk8c;         // 0x8c
+	MxCore* m_origin;        // 0x8c
 	MxLong m_unkTimingField; // 0x90
 };
 
diff --git a/LEGO1/mxdsmultiaction.h b/LEGO1/mxdsmultiaction.h
index 3c5f1eba..0190e4cd 100644
--- a/LEGO1/mxdsmultiaction.h
+++ b/LEGO1/mxdsmultiaction.h
@@ -36,9 +36,11 @@ class MxDSMultiAction : public MxDSAction {
 	virtual MxBool HasId(MxU32 p_objectId) override;                   // vtable+34;
 	virtual void SetUnkTimingField(MxLong p_unkTimingField) override;  // vtable+38;
 
+	inline MxDSActionList* GetActionList() const { return m_actions; };
+
 protected:
-	MxU32 m_sizeOnDisk;
-	MxDSActionList* m_actions;
+	MxU32 m_sizeOnDisk;        // 0x94
+	MxDSActionList* m_actions; // 0x98
 };
 
 // SYNTHETIC: LEGO1 0x1004ad10
diff --git a/LEGO1/mxdsobject.h b/LEGO1/mxdsobject.h
index 5bd7e144..4760b3ca 100644
--- a/LEGO1/mxdsobject.h
+++ b/LEGO1/mxdsobject.h
@@ -33,18 +33,16 @@ class MxDSObject : public MxCore {
 	virtual void Deserialize(char** p_source, MxS16 p_unk24);                       // vtable+1c;
 	inline virtual void SetAtomId(MxAtomId p_atomId) { this->m_atomId = p_atomId; } // vtable+20;
 
-	inline const MxAtomId& GetAtomId() { return this->m_atomId; }
+	inline MxDSType GetType() const { return (MxDSType) this->m_type; }
+	inline const char* GetSourceName() const { return this->m_sourceName; }
 	inline MxU32 GetObjectId() { return this->m_objectId; }
+	inline const MxAtomId& GetAtomId() { return this->m_atomId; }
 	inline MxS16 GetUnknown24() { return this->m_unk24; }
 
+	inline void SetType(MxDSType p_type) { this->m_type = p_type; }
 	inline void SetObjectId(MxU32 p_objectId) { this->m_objectId = p_objectId; }
 	inline void SetUnknown24(MxS16 p_unk24) { this->m_unk24 = p_unk24; }
 
-	inline const char* GetSourceName() const { return this->m_sourceName; }
-
-	inline void SetType(MxDSType p_type) { this->m_type = p_type; }
-	inline MxDSType GetType() const { return (MxDSType) this->m_type; }
-
 private:
 	MxU32 m_sizeOnDisk; // 0x8
 	MxU16 m_type;       // 0xc
diff --git a/LEGO1/mxlist.h b/LEGO1/mxlist.h
index 8ca3d199..83b465b9 100644
--- a/LEGO1/mxlist.h
+++ b/LEGO1/mxlist.h
@@ -60,7 +60,7 @@ class MxList : protected MxCollection<T> {
 	virtual ~MxList() override;
 
 	void Append(T p_obj) { _InsertEntry(p_obj, this->m_last, NULL); };
-	void DeleteAll();
+	void DeleteAll(MxBool p_destroy = TRUE);
 	MxU32 GetCount() { return this->m_count; }
 	void SetDestroy(void (*p_customDestructor)(T)) { this->m_customDestructor = p_customDestructor; }
 
@@ -95,6 +95,13 @@ class MxListCursor : public MxCore {
 	void Reset() { m_match = NULL; }
 	void Prepend(T p_newobj);
 
+	// TODO: Probably shouldn't exist
+	void NextFragment()
+	{
+		if (m_match)
+			m_match = m_match->GetNext();
+	}
+
 private:
 	MxList<T>* m_list;
 	MxListEntry<T>* m_match;
@@ -113,14 +120,17 @@ MxList<T>::~MxList()
 }
 
 template <class T>
-inline void MxList<T>::DeleteAll()
+inline void MxList<T>::DeleteAll(MxBool p_destroy)
 {
 	for (MxListEntry<T>* t = m_first;;) {
 		if (!t)
 			break;
 
 		MxListEntry<T>* next = t->GetNext();
-		this->m_customDestructor(t->GetValue());
+
+		if (p_destroy)
+			this->m_customDestructor(t->GetValue());
+
 		delete t;
 		t = next;
 	}
diff --git a/LEGO1/mxmediapresenter.cpp b/LEGO1/mxmediapresenter.cpp
index 314f89c7..b1b064cc 100644
--- a/LEGO1/mxmediapresenter.cpp
+++ b/LEGO1/mxmediapresenter.cpp
@@ -157,9 +157,9 @@ void MxMediaPresenter::EndAction()
 			m_subscriber = NULL;
 		}
 
-		if (action && action->GetUnknown8c()) {
+		if (action && action->GetOrigin()) {
 			NotificationManager()->Send(
-				action->GetUnknown8c(),
+				action->GetOrigin(),
 				&MxEndActionNotificationParam(c_notificationEndAction, this, action, FALSE)
 			);
 		}
diff --git a/LEGO1/mxnotificationmanager.h b/LEGO1/mxnotificationmanager.h
index a26f3748..9ab9c733 100644
--- a/LEGO1/mxnotificationmanager.h
+++ b/LEGO1/mxnotificationmanager.h
@@ -1,10 +1,10 @@
 #ifndef MXNOTIFICATIONMANAGER_H
 #define MXNOTIFICATIONMANAGER_H
 
-#include "compat.h"
 #include "mxcore.h"
 #include "mxcriticalsection.h"
 #include "mxnotificationparam.h"
+#include "mxstl/stlcompat.h"
 #include "mxtypes.h"
 
 class MxNotification {
diff --git a/LEGO1/mxpresenter.cpp b/LEGO1/mxpresenter.cpp
index cf11536e..4840c489 100644
--- a/LEGO1/mxpresenter.cpp
+++ b/LEGO1/mxpresenter.cpp
@@ -195,7 +195,7 @@ void MxPresenter::SendToCompositePresenter(MxOmni* p_omni)
 
 		NotificationManager()->Send(m_compositePresenter, &MxNotificationParam(MXPRESENTER_NOTIFICATION, this));
 
-		m_action->SetUnknown8c(p_omni ? p_omni : MxOmni::GetInstance());
+		m_action->SetOrigin(p_omni ? p_omni : MxOmni::GetInstance());
 		m_compositePresenter = NULL;
 	}
 }
diff --git a/LEGO1/mxpresenter.h b/LEGO1/mxpresenter.h
index 3e2c372f..963fb652 100644
--- a/LEGO1/mxpresenter.h
+++ b/LEGO1/mxpresenter.h
@@ -74,6 +74,11 @@ class MxPresenter : public MxCore {
 	inline MxS32 GetDisplayZ() const { return this->m_displayZ; }
 	inline MxDSAction* GetAction() const { return this->m_action; }
 
+	inline void SetCompositePresenter(MxCompositePresenter* p_compositePresenter)
+	{
+		m_compositePresenter = p_compositePresenter;
+	}
+
 protected:
 	__declspec(dllexport) void Init();
 	void SendToCompositePresenter(MxOmni*);
diff --git a/LEGO1/mxstl.h b/LEGO1/mxstl/mxstl.h
similarity index 100%
rename from LEGO1/mxstl.h
rename to LEGO1/mxstl/mxstl.h
diff --git a/LEGO1/mxstl/stlcompat.h b/LEGO1/mxstl/stlcompat.h
new file mode 100644
index 00000000..bc0076bf
--- /dev/null
+++ b/LEGO1/mxstl/stlcompat.h
@@ -0,0 +1,18 @@
+#ifndef STLCOMPAT_H
+#define STLCOMPAT_H
+
+#include "compat.h"
+
+#if defined(_MSC_VER) && _MSC_VER <= MSVC420_VERSION
+// Disable "nonstandard extension used : 'bool'" warning spam
+#pragma warning(disable : 4237)
+#include "mxstl.h"
+#else
+#include <algorithm>
+#include <list>
+#include <set>
+using std::list;
+using std::set;
+#endif
+
+#endif // STLCOMPAT_H
diff --git a/LEGO1/mxstreamcontroller.h b/LEGO1/mxstreamcontroller.h
index 0c63f3ba..8f6ca1c2 100644
--- a/LEGO1/mxstreamcontroller.h
+++ b/LEGO1/mxstreamcontroller.h
@@ -1,13 +1,13 @@
 #ifndef MXSTREAMCONTROLLER_H
 #define MXSTREAMCONTROLLER_H
 
-#include "compat.h" // STL
 #include "decomp.h"
 #include "mxatomid.h"
 #include "mxcore.h"
 #include "mxcriticalsection.h"
 #include "mxdsaction.h"
 #include "mxdsobject.h"
+#include "mxstl/stlcompat.h"
 #include "mxstreamlist.h"
 #include "mxstreamprovider.h"
 
diff --git a/LEGO1/mxstreamlist.h b/LEGO1/mxstreamlist.h
index 46024be5..2a9e7351 100644
--- a/LEGO1/mxstreamlist.h
+++ b/LEGO1/mxstreamlist.h
@@ -1,10 +1,10 @@
 #ifndef MXSTREAMLIST_H
 #define MXSTREAMLIST_H
 
-#include "compat.h" // STL
 #include "mxdsaction.h"
 #include "mxdssubscriber.h"
 #include "mxnextactiondatastart.h"
+#include "mxstl/stlcompat.h"
 
 template <class T>
 class MxStreamList : public list<T> {};
diff --git a/LEGO1/mxticklemanager.h b/LEGO1/mxticklemanager.h
index b7d90763..85994ef5 100644
--- a/LEGO1/mxticklemanager.h
+++ b/LEGO1/mxticklemanager.h
@@ -1,8 +1,8 @@
 #ifndef MXTICKLEMANAGER_H
 #define MXTICKLEMANAGER_H
 
-#include "compat.h"
 #include "mxcore.h"
+#include "mxstl/stlcompat.h"
 #include "mxtypes.h"
 
 class MxTickleClient {
diff --git a/LEGO1/realtime/matrix.cpp b/LEGO1/realtime/matrix.cpp
index 7b2a94b3..3ba63ca5 100644
--- a/LEGO1/realtime/matrix.cpp
+++ b/LEGO1/realtime/matrix.cpp
@@ -1,7 +1,7 @@
 
 #include "matrix.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 #include "math.h"
 
 #include <memory.h>
diff --git a/LEGO1/realtime/orientableroi.cpp b/LEGO1/realtime/orientableroi.cpp
index 651a1ac7..e03b78cb 100644
--- a/LEGO1/realtime/orientableroi.cpp
+++ b/LEGO1/realtime/orientableroi.cpp
@@ -1,6 +1,6 @@
 #include "orientableroi.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 DECOMP_SIZE_ASSERT(OrientableROI, 0xdc)
 
diff --git a/LEGO1/realtime/roi.h b/LEGO1/realtime/roi.h
index 66c17a84..40cff140 100644
--- a/LEGO1/realtime/roi.h
+++ b/LEGO1/realtime/roi.h
@@ -3,9 +3,9 @@
 
 // ROI stands for Real-time Object Instance.
 
-#include "../compat.h"
-#include "../mxstl.h"
+#include "../mxstl/stlcompat.h"
 #include "../realtime/realtime.h"
+#include "compat.h"
 #include "lodlist.h"
 #include "vector.h"
 
diff --git a/LEGO1/realtime/vector.cpp b/LEGO1/realtime/vector.cpp
index 1d41470c..54df74e4 100644
--- a/LEGO1/realtime/vector.cpp
+++ b/LEGO1/realtime/vector.cpp
@@ -1,7 +1,7 @@
 
 #include "vector.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 #include <math.h>
 #include <memory.h>
diff --git a/LEGO1/tgl/d3drm/impl.h b/LEGO1/tgl/d3drm/impl.h
index e6e05c7d..5ba877bb 100644
--- a/LEGO1/tgl/d3drm/impl.h
+++ b/LEGO1/tgl/d3drm/impl.h
@@ -1,6 +1,6 @@
 
-#include "../../decomp.h"
 #include "../tgl.h"
+#include "decomp.h"
 
 #include <d3drm.h>
 
diff --git a/LEGO1/viewmanager/viewlodlist.h b/LEGO1/viewmanager/viewlodlist.h
index 12817ff9..d695624f 100644
--- a/LEGO1/viewmanager/viewlodlist.h
+++ b/LEGO1/viewmanager/viewlodlist.h
@@ -1,9 +1,9 @@
 #ifndef VIEWLODLIST_H
 #define VIEWLODLIST_H
 
-#include "../compat.h"
 #include "../realtime/lodlist.h"
 #include "assert.h"
+#include "compat.h"
 
 #pragma warning(disable : 4786)
 
diff --git a/LEGO1/viewmanager/viewroi.cpp b/LEGO1/viewmanager/viewroi.cpp
index a15f1e2e..bb5dcaab 100644
--- a/LEGO1/viewmanager/viewroi.cpp
+++ b/LEGO1/viewmanager/viewroi.cpp
@@ -1,6 +1,6 @@
 #include "viewroi.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 DECOMP_SIZE_ASSERT(ViewROI, 0xe0)
 
diff --git a/LEGO1/compat.h b/util/compat.h
similarity index 71%
rename from LEGO1/compat.h
rename to util/compat.h
index 9616b254..c1175cd2 100644
--- a/LEGO1/compat.h
+++ b/util/compat.h
@@ -1,5 +1,5 @@
-#ifndef ISLECOMPAT_H
-#define ISLECOMPAT_H
+#ifndef COMPAT_H
+#define COMPAT_H
 
 // Various macros to enable compiling with other/newer compilers.
 
@@ -11,9 +11,6 @@
 #define COMPAT_CONST
 #endif
 
-// DIsable "nonstandard extension used : 'bool'" warning spam
-#pragma warning(disable : 4237)
-
 // Disable "identifier was truncated to '255' characters" warning.
 // Impossible to avoid this if using STL map or set.
 // This removes most (but not all) occurrences of the warning.
@@ -21,17 +18,6 @@
 
 #define MSVC420_VERSION 1020
 
-// STL compatibility.
-#if defined(_MSC_VER) && _MSC_VER <= MSVC420_VERSION
-#include "mxstl.h"
-#else
-#include <algorithm>
-#include <list>
-#include <set>
-using std::list;
-using std::set;
-#endif
-
 // We use `override` so newer compilers can tell us our vtables are valid,
 // however this keyword was added in C++11, so we define it as empty for
 // compatibility with older compilers.
@@ -39,4 +25,4 @@ using std::set;
 #define override
 #endif
 
-#endif // ISLECOMPAT_H
+#endif // COMPAT_H
diff --git a/LEGO1/decomp.h b/util/decomp.h
similarity index 100%
rename from LEGO1/decomp.h
rename to util/decomp.h