diff --git a/src/ai/ai.cpp b/src/ai/ai.cpp
new file mode 100644
--- /dev/null
+++ b/src/ai/ai.cpp
@@ -0,0 +1,247 @@
+/* $Id$ */
+
+#include "../stdafx.h"
+#include "../openttd.h"
+#include "../variables.h"
+#include "../command.h"
+#include "../network/network.h"
+#include "ai.h"
+#include "default/default.h"
+
+/**
+ * Dequeues commands put in the queue via AI_PutCommandInQueue.
+ */
+static void AI_DequeueCommands(PlayerID player)
+{
+	AICommand *com, *entry_com;
+
+	entry_com = _ai_player[player].queue;
+
+	/* It happens that DoCommandP issues a new DoCommandAI which adds a new command
+	 *  to this very same queue (don't argue about this, if it currently doesn't
+	 *  happen I can tell you it will happen with AIScript -- TrueLight). If we
+	 *  do not make the queue NULL, that commands will be dequeued immediatly.
+	 *  Therefor we safe the entry-point to entry_com, and make the queue NULL, so
+	 *  the new queue can be safely built up. */
+	_ai_player[player].queue = NULL;
+	_ai_player[player].queue_tail = NULL;
+
+	/* Dequeue all commands */
+	while ((com = entry_com) != NULL) {
+		_current_player = player;
+
+		_cmd_text = com->text;
+		DoCommandP(com->tile, com->p1, com->p2, com->callback, com->procc);
+
+		/* Free item */
+		entry_com = com->next;
+		free(com->text);
+		free(com);
+	}
+}
+
+/**
+ * Needed for SP; we need to delay DoCommand with 1 tick, because else events
+ *  will make infinite loops (AIScript).
+ */
+static void AI_PutCommandInQueue(PlayerID player, TileIndex tile, uint32 p1, uint32 p2, uint procc, CommandCallback* callback)
+{
+	AICommand *com;
+
+	if (_ai_player[player].queue_tail == NULL) {
+		/* There is no item in the queue yet, create the queue */
+		_ai_player[player].queue = malloc(sizeof(AICommand));
+		_ai_player[player].queue_tail = _ai_player[player].queue;
+	} else {
+		/* Add an item at the end */
+		_ai_player[player].queue_tail->next = malloc(sizeof(AICommand));
+		_ai_player[player].queue_tail = _ai_player[player].queue_tail->next;
+	}
+
+	/* This is our new item */
+	com = _ai_player[player].queue_tail;
+
+	/* Assign the info */
+	com->tile  = tile;
+	com->p1    = p1;
+	com->p2    = p2;
+	com->procc = procc;
+	com->callback = callback;
+	com->next  = NULL;
+	com->text  = NULL;
+
+	/* Copy the cmd_text, if needed */
+	if (_cmd_text != NULL) {
+		com->text = strdup(_cmd_text);
+		_cmd_text = NULL;
+	}
+}
+
+/**
+ * Executes a raw DoCommand for the AI.
+ */
+int32 AI_DoCommandCc(TileIndex tile, uint32 p1, uint32 p2, uint32 flags, uint procc, CommandCallback* callback)
+{
+	PlayerID old_lp;
+	int32 res = 0;
+	const char* tmp_cmdtext;
+
+	/* If you enable DC_EXEC with DC_QUERY_COST you are a really strange
+	 *   person.. should we check for those funny jokes?
+	 */
+
+	/* The test already resets _cmd_text, so backup the pointer */
+	tmp_cmdtext = _cmd_text;
+
+	/* First, do a test-run to see if we can do this */
+	res = DoCommand(tile, p1, p2, flags & ~DC_EXEC, procc);
+	/* The command failed, or you didn't want to execute, or you are quering, return */
+	if (CmdFailed(res) || !(flags & DC_EXEC) || (flags & DC_QUERY_COST)) {
+		return res;
+	}
+
+	/* Restore _cmd_text */
+	_cmd_text = tmp_cmdtext;
+
+	/* If we did a DC_EXEC, and the command did not return an error, execute it
+	 * over the network */
+	if (flags & DC_AUTO)     procc |= CMD_AUTO;
+	if (flags & DC_NO_WATER) procc |= CMD_NO_WATER;
+
+	/* NetworkSend_Command needs _local_player to be set correctly, so
+	 * adjust it, and put it back right after the function */
+	old_lp = _local_player;
+	_local_player = _current_player;
+
+#ifdef ENABLE_NETWORK
+	/* Send the command */
+	if (_networking) {
+		/* Network is easy, send it to his handler */
+		NetworkSend_Command(tile, p1, p2, procc, callback);
+	} else {
+#else
+	{
+#endif
+		/* If we execute BuildCommands directly in SP, we have a big problem with events
+		 *  so we need to delay is for 1 tick */
+		AI_PutCommandInQueue(_current_player, tile, p1, p2, procc, callback);
+	}
+
+	/* Set _local_player back */
+	_local_player = old_lp;
+
+	return res;
+}
+
+
+int32 AI_DoCommand(TileIndex tile, uint32 p1, uint32 p2, uint32 flags, uint procc)
+{
+	return AI_DoCommandCc(tile, p1, p2, flags, procc, NULL);
+}
+
+
+/**
+ * Run 1 tick of the AI. Don't overdo it, keep it realistic.
+ */
+static void AI_RunTick(PlayerID player)
+{
+	extern void AiNewDoGameLoop(Player *p);
+
+	Player *p = GetPlayer(player);
+	_current_player = player;
+
+	if (_patches.ainew_active) {
+		AiNewDoGameLoop(p);
+	} else {
+		/* Enable all kind of cheats the old AI needs in order to operate correctly... */
+		_is_old_ai_player = true;
+		AiDoGameLoop(p);
+		_is_old_ai_player = false;
+	}
+}
+
+
+/**
+ * The gameloop for AIs.
+ *  Handles one tick for all the AIs.
+ */
+void AI_RunGameLoop(void)
+{
+	/* Don't do anything if ai is disabled */
+	if (!_ai.enabled) return;
+
+	/* Don't do anything if we are a network-client, or the AI has been disabled */
+	if (_networking && (!_network_server || !_patches.ai_in_multiplayer)) return;
+
+	/* New tick */
+	_ai.tick++;
+
+	/* Make sure the AI follows the difficulty rule.. */
+	assert(_opt.diff.competitor_speed <= 4);
+	if ((_ai.tick & ((1 << (4 - _opt.diff.competitor_speed)) - 1)) != 0) return;
+
+	/* Check for AI-client (so joining a network with an AI) */
+	if (!_networking || _network_server) {
+		/* Check if we want to run AIs (server or SP only) */
+		const Player* p;
+
+		FOR_ALL_PLAYERS(p) {
+			if (p->is_active && p->is_ai) {
+				/* This should always be true, else something went wrong... */
+				assert(_ai_player[p->index].active);
+
+				/* Run the script */
+				AI_DequeueCommands(p->index);
+				AI_RunTick(p->index);
+			}
+		}
+	}
+
+	_current_player = OWNER_NONE;
+}
+
+/**
+ * A new AI sees the day of light. You can do here what ever you think is needed.
+ */
+void AI_StartNewAI(PlayerID player)
+{
+	assert(IsValidPlayer(player));
+
+	/* Called if a new AI is booted */
+	_ai_player[player].active = true;
+}
+
+/**
+ * This AI player died. Give it some chance to make a final puf.
+ */
+void AI_PlayerDied(PlayerID player)
+{
+	/* Called if this AI died */
+	_ai_player[player].active = false;
+}
+
+/**
+ * Initialize some AI-related stuff.
+ */
+void AI_Initialize(void)
+{
+	/* First, make sure all AIs are DEAD! */
+	AI_Uninitialize();
+
+	memset(&_ai, 0, sizeof(_ai));
+	memset(&_ai_player, 0, sizeof(_ai_player));
+
+	_ai.enabled = true;
+}
+
+/**
+ * Deinitializer for AI-related stuff.
+ */
+void AI_Uninitialize(void)
+{
+	const Player* p;
+
+	FOR_ALL_PLAYERS(p) {
+		if (p->is_active && p->is_ai) AI_PlayerDied(p->index);
+	}
+}