diff --git a/src/ai/ai_instance.cpp b/src/ai/ai_instance.cpp
new file mode 100644
--- /dev/null
+++ b/src/ai/ai_instance.cpp
@@ -0,0 +1,628 @@
+/* $Id$ */
+
+/** @file ai_instance.cpp Implementation of AIInstance. */
+
+#include "../stdafx.h"
+#include "../openttd.h"
+#include "../debug.h"
+#include "../company_func.h"
+#include "../core/alloc_func.hpp"
+#include "../string_func.h"
+#include "../settings_type.h"
+#include "../company_base.h"
+#include "../saveload/saveload.h"
+#include "table/strings.h"
+
+#include <squirrel.h>
+#include "../script/squirrel.hpp"
+#include "../script/squirrel_helper.hpp"
+#include "../script/squirrel_class.hpp"
+#include "../script/squirrel_std.hpp"
+#include "ai.hpp"
+#include "api/ai_controller.hpp"
+#include "ai_info.hpp"
+#include "ai_storage.hpp"
+#include "ai_instance.hpp"
+
+/* Convert all AI related classes to Squirrel data.
+ * Note: this line a marker in squirrel_export.sh. Do not change! */
+#include "api/ai_abstractlist.hpp.sq"
+#include "api/ai_accounting.hpp.sq"
+#include "api/ai_airport.hpp.sq"
+#include "api/ai_base.hpp.sq"
+#include "api/ai_bridge.hpp.sq"
+#include "api/ai_bridgelist.hpp.sq"
+#include "api/ai_cargo.hpp.sq"
+#include "api/ai_cargolist.hpp.sq"
+#include "api/ai_company.hpp.sq"
+#include "api/ai_controller.hpp.sq"
+#include "api/ai_date.hpp.sq"
+#include "api/ai_depotlist.hpp.sq"
+#include "api/ai_engine.hpp.sq"
+#include "api/ai_enginelist.hpp.sq"
+#include "api/ai_error.hpp.sq"
+#include "api/ai_event.hpp.sq"
+#include "api/ai_event_types.hpp.sq"
+#include "api/ai_execmode.hpp.sq"
+#include "api/ai_gamesettings.hpp.sq"
+#include "api/ai_group.hpp.sq"
+#include "api/ai_grouplist.hpp.sq"
+#include "api/ai_industry.hpp.sq"
+#include "api/ai_industrylist.hpp.sq"
+#include "api/ai_industrytype.hpp.sq"
+#include "api/ai_industrytypelist.hpp.sq"
+#include "api/ai_list.hpp.sq"
+#include "api/ai_log.hpp.sq"
+#include "api/ai_map.hpp.sq"
+#include "api/ai_marine.hpp.sq"
+#include "api/ai_order.hpp.sq"
+#include "api/ai_rail.hpp.sq"
+#include "api/ai_railtypelist.hpp.sq"
+#include "api/ai_road.hpp.sq"
+#include "api/ai_sign.hpp.sq"
+#include "api/ai_station.hpp.sq"
+#include "api/ai_stationlist.hpp.sq"
+#include "api/ai_subsidy.hpp.sq"
+#include "api/ai_subsidylist.hpp.sq"
+#include "api/ai_testmode.hpp.sq"
+#include "api/ai_tile.hpp.sq"
+#include "api/ai_tilelist.hpp.sq"
+#include "api/ai_town.hpp.sq"
+#include "api/ai_townlist.hpp.sq"
+#include "api/ai_tunnel.hpp.sq"
+#include "api/ai_vehicle.hpp.sq"
+#include "api/ai_vehiclelist.hpp.sq"
+
+/* static */ AIInstance *AIInstance::current_instance = NULL;
+
+AIStorage::~AIStorage()
+{
+	/* Free our pointers */
+	if (event_data != NULL) AIEventController::FreeEventPointer();
+	if (log_data != NULL) AILog::FreeLogPointer();
+}
+
+static void PrintFunc(bool error_msg, const SQChar *message)
+{
+	/* Convert to OpenTTD internal capable string */
+	AIController::Print(error_msg, FS2OTTD(message));
+}
+
+AIInstance::AIInstance(AIInfo *info) :
+	controller(NULL),
+	storage(NULL),
+	engine(NULL),
+	instance(NULL),
+	is_started(false),
+	is_dead(false),
+	suspend(0),
+	callback(NULL)
+{
+	/* Set the instance already, so we can use AIObject::Set commands */
+	GetCompany(_current_company)->ai_instance = this;
+	AIInstance::current_instance = this;
+
+	this->controller = new AIController();
+	this->storage    = new AIStorage();
+	this->engine     = new Squirrel();
+	this->engine->SetPrintFunction(&PrintFunc);
+
+	/* The import method is available at a very early stage */
+	this->engine->AddMethod("import", &AILibrary::Import, 4, "?ssi");
+
+	/* Register the AIController */
+	SQAIController_Register(this->engine);
+
+	/* Load and execute the script for this AI */
+	const char *script_name = info->GetScriptName();
+	if (strcmp(script_name, "%_dummy") == 0) {
+		extern void AI_CreateAIDummy(HSQUIRRELVM vm);
+		AI_CreateAIDummy(this->engine->GetVM());
+	} else if (!this->engine->LoadScript(script_name)) {
+		this->Died();
+		return;
+	}
+
+	/* Create the main-class */
+	this->instance = MallocT<SQObject>(1);
+	if (!this->engine->CreateClassInstance(info->GetInstanceName(), this->controller, this->instance)) {
+		this->Died();
+		return;
+	}
+
+	/* Register the API functions and classes */
+	this->RegisterAPI();
+
+	/* Run the constructor if it exists. Don't allow any DoCommands in it. */
+	if (this->engine->MethodExists(*this->instance, "constructor")) {
+		AIObject::SetAllowDoCommand(false);
+		this->engine->CallMethod(*this->instance, "constructor");
+		AIObject::SetAllowDoCommand(true);
+	}
+}
+
+AIInstance::~AIInstance()
+{
+	if (engine != NULL) delete this->engine;
+	delete this->storage;
+	delete this->controller;
+	free(this->instance);
+}
+
+void AIInstance::RegisterAPI()
+{
+/* Register all classes */
+	squirrel_register_std(this->engine);
+	SQAIAbstractList_Register(this->engine);
+	SQAIAccounting_Register(this->engine);
+	SQAIAirport_Register(this->engine);
+	SQAIBase_Register(this->engine);
+	SQAIBridge_Register(this->engine);
+	SQAIBridgeList_Register(this->engine);
+	SQAIBridgeList_Length_Register(this->engine);
+	SQAICargo_Register(this->engine);
+	SQAICargoList_Register(this->engine);
+	SQAICargoList_IndustryAccepting_Register(this->engine);
+	SQAICargoList_IndustryProducing_Register(this->engine);
+	SQAICompany_Register(this->engine);
+	SQAIDate_Register(this->engine);
+	SQAIDepotList_Register(this->engine);
+	SQAIEngine_Register(this->engine);
+	SQAIEngineList_Register(this->engine);
+	SQAIError_Register(this->engine);
+	SQAIEvent_Register(this->engine);
+	SQAIEventCompanyBankrupt_Register(this->engine);
+	SQAIEventCompanyInTrouble_Register(this->engine);
+	SQAIEventCompanyMerger_Register(this->engine);
+	SQAIEventCompanyNew_Register(this->engine);
+	SQAIEventController_Register(this->engine);
+	SQAIEventEngineAvailable_Register(this->engine);
+	SQAIEventEnginePreview_Register(this->engine);
+	SQAIEventIndustryClose_Register(this->engine);
+	SQAIEventIndustryOpen_Register(this->engine);
+	SQAIEventStationFirstVehicle_Register(this->engine);
+	SQAIEventSubsidyAwarded_Register(this->engine);
+	SQAIEventSubsidyExpired_Register(this->engine);
+	SQAIEventSubsidyOffer_Register(this->engine);
+	SQAIEventSubsidyOfferExpired_Register(this->engine);
+	SQAIEventTest_Register(this->engine);
+	SQAIEventVehicleCrashed_Register(this->engine);
+	SQAIEventVehicleLost_Register(this->engine);
+	SQAIEventVehicleUnprofitable_Register(this->engine);
+	SQAIEventVehicleWaitingInDepot_Register(this->engine);
+	SQAIExecMode_Register(this->engine);
+	SQAIGameSettings_Register(this->engine);
+	SQAIGroup_Register(this->engine);
+	SQAIGroupList_Register(this->engine);
+	SQAIIndustry_Register(this->engine);
+	SQAIIndustryList_Register(this->engine);
+	SQAIIndustryList_CargoAccepting_Register(this->engine);
+	SQAIIndustryList_CargoProducing_Register(this->engine);
+	SQAIIndustryType_Register(this->engine);
+	SQAIIndustryTypeList_Register(this->engine);
+	SQAIList_Register(this->engine);
+	SQAILog_Register(this->engine);
+	SQAIMap_Register(this->engine);
+	SQAIMarine_Register(this->engine);
+	SQAIOrder_Register(this->engine);
+	SQAIRail_Register(this->engine);
+	SQAIRailTypeList_Register(this->engine);
+	SQAIRoad_Register(this->engine);
+	SQAISign_Register(this->engine);
+	SQAIStation_Register(this->engine);
+	SQAIStationList_Register(this->engine);
+	SQAIStationList_Vehicle_Register(this->engine);
+	SQAISubsidy_Register(this->engine);
+	SQAISubsidyList_Register(this->engine);
+	SQAITestMode_Register(this->engine);
+	SQAITile_Register(this->engine);
+	SQAITileList_Register(this->engine);
+	SQAITileList_IndustryAccepting_Register(this->engine);
+	SQAITileList_IndustryProducing_Register(this->engine);
+	SQAITileList_StationType_Register(this->engine);
+	SQAITown_Register(this->engine);
+	SQAITownList_Register(this->engine);
+	SQAITunnel_Register(this->engine);
+	SQAIVehicle_Register(this->engine);
+	SQAIVehicleList_Register(this->engine);
+	SQAIVehicleList_Station_Register(this->engine);
+
+	this->engine->SetGlobalPointer(this->engine);
+}
+
+void AIInstance::Continue()
+{
+	assert(this->suspend < 0);
+	this->suspend = -this->suspend - 1;
+}
+
+void AIInstance::Died()
+{
+	DEBUG(ai, 0, "The AI died unexpectedly.");
+	this->is_dead = true;
+
+	delete this->engine;
+	this->engine = NULL;
+}
+
+void AIInstance::GameLoop()
+{
+	if (this->is_dead) return;
+	this->controller->ticks++;
+
+	if (this->suspend   < -1) this->suspend++; // Multiplayer suspend, increase up to -1.
+	if (this->suspend   < 0)  return;          // Multiplayer suspend, wait for Continue().
+	if (--this->suspend > 0)  return;          // Singleplayer suspend, decrease to 0.
+
+	/* If there is a callback to call, call that first */
+	if (this->callback != NULL) {
+		try {
+			this->callback(this);
+		} catch (AI_VMSuspend e) {
+			this->suspend  = e.GetSuspendTime();
+			this->callback = e.GetSuspendCallback();
+
+			return;
+		}
+	}
+
+	this->suspend  = 0;
+	this->callback = NULL;
+
+	if (!this->is_started) {
+		/* Start the AI by calling Start() */
+		try {
+			if (!this->engine->CallMethod(*this->instance, "Start",  _settings_game.ai.ai_max_opcode_till_suspend)) this->Died();
+		} catch (AI_VMSuspend e) {
+			this->suspend  = e.GetSuspendTime();
+			this->callback = e.GetSuspendCallback();
+		}
+
+		this->is_started = true;
+		return;
+	}
+
+	/* Continue the VM */
+	try {
+		if (!this->engine->Resume(_settings_game.ai.ai_max_opcode_till_suspend)) this->Died();
+	} catch (AI_VMSuspend e) {
+		this->suspend  = e.GetSuspendTime();
+		this->callback = e.GetSuspendCallback();
+	}
+}
+
+/* static */ void AIInstance::DoCommandReturn(AIInstance *instance)
+{
+	instance->engine->InsertResult(AIObject::GetLastCommandRes());
+}
+
+/* static */ void AIInstance::DoCommandReturnVehicleID(AIInstance *instance)
+{
+	instance->engine->InsertResult(AIObject::GetNewVehicleID());
+}
+
+/* static */ void AIInstance::DoCommandReturnSignID(AIInstance *instance)
+{
+	instance->engine->InsertResult(AIObject::GetNewSignID());
+}
+
+/* static */ void AIInstance::DoCommandReturnGroupID(AIInstance *instance)
+{
+	instance->engine->InsertResult(AIObject::GetNewGroupID());
+}
+
+/* static */ AIStorage *AIInstance::GetStorage()
+{
+	assert(IsValidCompanyID(_current_company) && !IsHumanCompany(_current_company));
+	return GetCompany(_current_company)->ai_instance->storage;
+}
+
+/*
+ * All data is stored in the following format:
+ * First 1 byte indicating if there is a data blob at all.
+ * 1 byte indicating the type of data.
+ * The data itself, this differs per type:
+ *  - integer: a binary representation of the integer (int32).
+ *  - string:  First one byte with the string length, then a 0-terminated char
+ *             array. The string can't be longer then 255 bytes (including
+ *             terminating '\0').
+ *  - array:   All data-elements of the array are saved recursive in this
+ *             format, and ended with an element of the type
+ *             SQSL_ARRAY_TABLE_END.
+ *  - table:   All key/value pairs are saved in this format (first key 1, then
+ *             value 1, then key 2, etc.). All keys and values can have an
+ *             arbitrary type (as long as it is supported by the save function
+ *             of course). The table is ended with an element of the type
+ *             SQSL_ARRAY_TABLE_END.
+ *  - bool:    A single byte with value 1 representing true and 0 false.
+ *  - null:    No data.
+ */
+
+/** The type of the data that follows in the savegame. */
+enum SQSaveLoadType {
+	SQSL_INT             = 0x00, ///< The following data is an integer.
+	SQSL_STRING          = 0x01, ///< The following data is an string.
+	SQSL_ARRAY           = 0x02, ///< The following data is an array.
+	SQSL_TABLE           = 0x03, ///< The following data is an table.
+	SQSL_BOOL            = 0x04, ///< The following data is a boolean.
+	SQSL_NULL            = 0x05, ///< A null variable.
+	SQSL_ARRAY_TABLE_END = 0xFF, ///< Marks the end of an array or table, no data follows.
+};
+
+static byte _ai_sl_byte;
+
+static const SaveLoad _ai_byte[] = {
+	SLEG_VAR(_ai_sl_byte, SLE_UINT8),
+	SLE_END()
+};
+
+enum {
+	AISAVE_MAX_DEPTH = 25, ///< The maximum recursive depth for items stored in the savegame.
+};
+
+/* static */ bool AIInstance::SaveObject(HSQUIRRELVM vm, SQInteger index, int max_depth, bool test)
+{
+	if (max_depth == 0) {
+		AILog::Error("Savedata can only be nested to 5 deep. No data saved.");
+		return false;
+	}
+
+	switch (sq_gettype(vm, index)) {
+		case OT_INTEGER: {
+			if (!test) {
+				_ai_sl_byte = SQSL_INT;
+				SlObject(NULL, _ai_byte);
+			}
+			SQInteger res;
+			sq_getinteger(vm, index, &res);
+			if (!test) {
+				int value = (int)res;
+				SlArray(&value, 1, SLE_INT32);
+			}
+			return true;
+		}
+
+		case OT_STRING: {
+			if (!test) {
+				_ai_sl_byte = SQSL_STRING;
+				SlObject(NULL, _ai_byte);
+			}
+			const SQChar *res;
+			sq_getstring(vm, index, &res);
+			/* @bug if a string longer than 512 characters is given to FS2OTTD, the
+			 *  internal buffer overflows. */
+			const char *buf = FS2OTTD(res);
+			size_t len = strlen(buf) + 1;
+			if (len >= 255) {
+				AILog::Error("Maximum string length is 254 chars. No data saved.");
+				return false;
+			}
+			if (!test) {
+				_ai_sl_byte = (byte)len;
+				SlObject(NULL, _ai_byte);
+				SlArray((void*)buf, len, SLE_CHAR);
+			}
+			return true;
+		}
+
+		case OT_ARRAY: {
+			if (!test) {
+				_ai_sl_byte = SQSL_ARRAY;
+				SlObject(NULL, _ai_byte);
+			}
+			sq_pushnull(vm);
+			while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
+				/* Store the value */
+				bool res = SaveObject(vm, -1, max_depth - 1, test);
+				sq_pop(vm, 2);
+				if (!res) {
+					sq_pop(vm, 1);
+					return false;
+				}
+			}
+			sq_pop(vm, 1);
+			if (!test) {
+				_ai_sl_byte = SQSL_ARRAY_TABLE_END;
+				SlObject(NULL, _ai_byte);
+			}
+			return true;
+		}
+
+		case OT_TABLE: {
+			if (!test) {
+				_ai_sl_byte = SQSL_TABLE;
+				SlObject(NULL, _ai_byte);
+			}
+			sq_pushnull(vm);
+			while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
+				/* Store the key + value */
+				bool res = SaveObject(vm, -2, max_depth - 1, test) && SaveObject(vm, -1, max_depth - 1, test);
+				sq_pop(vm, 2);
+				if (!res) {
+					sq_pop(vm, 1);
+					return false;
+				}
+			}
+			sq_pop(vm, 1);
+			if (!test) {
+				_ai_sl_byte = SQSL_ARRAY_TABLE_END;
+				SlObject(NULL, _ai_byte);
+			}
+			return true;
+		}
+
+		case OT_BOOL: {
+			if (!test) {
+				_ai_sl_byte = SQSL_BOOL;
+				SlObject(NULL, _ai_byte);
+			}
+			SQBool res;
+			sq_getbool(vm, index, &res);
+			if (!test) {
+				_ai_sl_byte = res ? 1 : 0;
+				SlObject(NULL, _ai_byte);
+			}
+			return true;
+		}
+
+		case OT_NULL: {
+			if (!test) {
+				_ai_sl_byte = SQSL_NULL;
+				SlObject(NULL, _ai_byte);
+			}
+			return true;
+		}
+
+		default:
+			AILog::Error("You tried to save unsupported type. No data saved.");
+			return false;
+	}
+}
+
+/* static */ void AIInstance::SaveEmpty()
+{
+	_ai_sl_byte = 0;
+	SlObject(NULL, _ai_byte);
+}
+
+void AIInstance::Save()
+{
+	/* Don't save data if the AI didn't start yet. */
+	if (this->engine == NULL) {
+		SaveEmpty();
+		return;
+	}
+
+	/* We don't want to be interrupted during the save function. */
+	AIObject::SetAllowDoCommand(false);
+
+	HSQOBJECT savedata;
+	if (this->engine->MethodExists(*this->instance, "Save")) {
+		this->engine->CallMethod(*this->instance, "Save", &savedata);
+		if (!sq_istable(savedata)) {
+			AILog::Error("Save function should return a table.");
+			_ai_sl_byte = 0;
+			SlObject(NULL, _ai_byte);
+			AIObject::SetAllowDoCommand(true);
+			return;
+		}
+		HSQUIRRELVM vm = this->engine->GetVM();
+		sq_pushobject(vm, savedata);
+		if (SaveObject(vm, -1, AISAVE_MAX_DEPTH, true)) {
+			_ai_sl_byte = 1;
+			SlObject(NULL, _ai_byte);
+			SaveObject(vm, -1, AISAVE_MAX_DEPTH, false);
+		} else {
+			_ai_sl_byte = 0;
+			SlObject(NULL, _ai_byte);
+		}
+		sq_pop(vm, 1);
+	} else {
+		AILog::Warning("Save function is not implemented");
+		_ai_sl_byte = 0;
+		SlObject(NULL, _ai_byte);
+	}
+
+	AIObject::SetAllowDoCommand(true);
+}
+
+/* static */ bool AIInstance::LoadObjects(HSQUIRRELVM vm)
+{
+	SlObject(NULL, _ai_byte);
+	switch (_ai_sl_byte) {
+		case SQSL_INT: {
+			int value;
+			SlArray(&value, 1, SLE_INT32);
+			if (vm != NULL) sq_pushinteger(vm, (SQInteger)value);
+			return true;
+		}
+
+		case SQSL_STRING: {
+			SlObject(NULL, _ai_byte);
+			static char buf[256];
+			SlArray(buf, _ai_sl_byte, SLE_CHAR);
+			if (vm != NULL) sq_pushstring(vm, OTTD2FS(buf), -1);
+			return true;
+		}
+
+		case SQSL_ARRAY: {
+			if (vm != NULL) sq_newarray(vm, 0);
+			while (LoadObjects(vm)) {
+				if (vm != NULL) sq_arrayappend(vm, -2);
+				/* The value is popped from the stack by squirrel. */
+			}
+			return true;
+		}
+
+		case SQSL_TABLE: {
+			if (vm != NULL) sq_newtable(vm);
+			while (LoadObjects(vm)) {
+				LoadObjects(vm);
+				if (vm != NULL) sq_rawset(vm, -3);
+				/* The key (-2) and value (-1) are popped from the stack by squirrel. */
+			}
+			return true;
+		}
+
+		case SQSL_BOOL: {
+			SlObject(NULL, _ai_byte);
+			if (vm != NULL) sq_pushinteger(vm, (SQBool)(_ai_sl_byte != 0));
+			return true;
+		}
+
+		case SQSL_NULL: {
+			if (vm != NULL) sq_pushnull(vm);
+			return true;
+		}
+
+		case SQSL_ARRAY_TABLE_END: {
+			return false;
+		}
+
+		default: NOT_REACHED();
+	}
+}
+
+/* static */ void AIInstance::LoadEmpty()
+{
+	SlObject(NULL, _ai_byte);
+	/* Check if there was anything saved at all. */
+	if (_ai_sl_byte == 0) return;
+
+	LoadObjects(NULL);
+}
+
+bool AIInstance::Load()
+{
+	HSQUIRRELVM vm = (this->engine == NULL) ? NULL : this->engine->GetVM();
+
+	SlObject(NULL, _ai_byte);
+	/* Check if there was anything saved at all. */
+	if (_ai_sl_byte == 0) return true;
+	AIObject::SetAllowDoCommand(false);
+
+	if (vm != NULL) {
+		/* Go to the instance-root */
+		sq_pushobject(vm, *this->instance);
+		/* Find the function-name inside the script */
+		sq_pushstring(vm, OTTD2FS("Load"), -1);
+		if (SQ_FAILED(sq_get(vm, -2))) sq_pushnull(vm);
+		sq_pushobject(vm, *this->instance);
+	}
+
+	LoadObjects(vm);
+
+	if (this->engine != NULL) {
+		if (this->engine->MethodExists(*this->instance, "Load")) {
+			sq_call(vm, 2, SQFalse, SQFalse);
+		} else {
+			AILog::Warning("Loading failed: there was data for the AI to load, but the AI does not have a Load() function.");
+		}
+	}
+
+	/* Pop 1) the object instance, 2) the function name, 3) the instance again, 4) the table. */
+	if (vm != NULL) sq_pop(vm, 4);
+
+	AIObject::SetAllowDoCommand(true);
+	return true;
+}