diff --git a/src/inventory.cpp b/src/inventory.cpp
index a610a46..86e0087 100644
--- a/src/inventory.cpp
+++ b/src/inventory.cpp
@@ -403,6 +403,28 @@ InventoryItem * InventoryList::addItem(u32 i, InventoryItem *newitem)
 	}
 }
 
+bool InventoryList::itemFits(u32 i, InventoryItem *newitem)
+{
+	// If it is an empty position, it's an easy job.
+	InventoryItem *to_item = m_items[i];
+	if(to_item == NULL)
+	{
+		return true;
+	}
+	
+	// If not addable, return the item
+	if(newitem->addableTo(to_item) == false)
+		return false;
+	
+	// If the item fits fully in the slot, add counter and delete it
+	if(newitem->getCount() <= to_item->freeSpace())
+	{
+		return true;
+	}
+
+	return false;
+}
+
 InventoryItem * InventoryList::takeItem(u32 i, u32 count)
 {
 	if(count == 0)
@@ -698,5 +720,132 @@ void IMoveAction::apply(InventoryContext *c, InventoryManager *mgr)
 		mgr->inventoryModified(c, to_inv);
 #endif
 }
+
+/*
+	Craft checking system
+*/
+
+bool ItemSpec::checkItem(InventoryItem *item)
+{
+	if(type == ITEM_NONE)
+	{
+		// Has to be no item
+		if(item != NULL)
+			return false;
+		return true;
+	}
+	
+	// There should be an item
+	if(item == NULL)
+		return false;
+
+	std::string itemname = item->getName();
+
+	if(type == ITEM_MATERIAL)
+	{
+		if(itemname != "MaterialItem")
+			return false;
+		MaterialItem *mitem = (MaterialItem*)item;
+		if(mitem->getMaterial() != num)
+			return false;
+	}
+	else if(type == ITEM_CRAFT)
+	{
+		if(itemname != "CraftItem")
+			return false;
+		CraftItem *mitem = (CraftItem*)item;
+		if(mitem->getSubName() != name)
+			return false;
+	}
+	else if(type == ITEM_TOOL)
+	{
+		// Not supported yet
+		assert(0);
+	}
+	else if(type == ITEM_MBO)
+	{
+		// Not supported yet
+		assert(0);
+	}
+	else
+	{
+		// Not supported yet
+		assert(0);
+	}
+	return true;
+}
+
+bool checkItemCombination(InventoryItem **items, ItemSpec *specs)
+{
+	u16 items_min_x = 100;
+	u16 items_max_x = 100;
+	u16 items_min_y = 100;
+	u16 items_max_y = 100;
+	for(u16 y=0; y<3; y++)
+	for(u16 x=0; x<3; x++)
+	{
+		if(items[y*3 + x] == NULL)
+			continue;
+		if(items_min_x == 100 || x < items_min_x)
+			items_min_x = x;
+		if(items_min_y == 100 || y < items_min_y)
+			items_min_y = y;
+		if(items_max_x == 100 || x > items_max_x)
+			items_max_x = x;
+		if(items_max_y == 100 || y > items_max_y)
+			items_max_y = y;
+	}
+	// No items at all, just return false
+	if(items_min_x == 100)
+		return false;
+	
+	u16 items_w = items_max_x - items_min_x + 1;
+	u16 items_h = items_max_y - items_min_y + 1;
+
+	u16 specs_min_x = 100;
+	u16 specs_max_x = 100;
+	u16 specs_min_y = 100;
+	u16 specs_max_y = 100;
+	for(u16 y=0; y<3; y++)
+	for(u16 x=0; x<3; x++)
+	{
+		if(specs[y*3 + x].type == ITEM_NONE)
+			continue;
+		if(specs_min_x == 100 || x < specs_min_x)
+			specs_min_x = x;
+		if(specs_min_y == 100 || y < specs_min_y)
+			specs_min_y = y;
+		if(specs_max_x == 100 || x > specs_max_x)
+			specs_max_x = x;
+		if(specs_max_y == 100 || y > specs_max_y)
+			specs_max_y = y;
+	}
+	// No specs at all, just return false
+	if(specs_min_x == 100)
+		return false;
+
+	u16 specs_w = specs_max_x - specs_min_x + 1;
+	u16 specs_h = specs_max_y - specs_min_y + 1;
+
+	// Different sizes
+	if(items_w != specs_w || items_h != specs_h)
+		return false;
+
+	for(u16 y=0; y<specs_h; y++)
+	for(u16 x=0; x<specs_w; x++)
+	{
+		u16 items_x = items_min_x + x;
+		u16 items_y = items_min_y + y;
+		u16 specs_x = specs_min_x + x;
+		u16 specs_y = specs_min_y + y;
+		InventoryItem *item = items[items_y * 3 + items_x];
+		ItemSpec &spec = specs[specs_y * 3 + specs_x];
+
+		if(spec.checkItem(item) == false)
+			return false;
+	}
+
+	return true;
+}
 	
 //END
diff --git a/src/inventory.h b/src/inventory.h
index 45bc488..0cbd97a 100644
--- a/src/inventory.h
+++ b/src/inventory.h
@@ -435,6 +435,7 @@ public:
 	InventoryItem * changeItem(u32 i, InventoryItem *newitem);
 	// Delete item
 	void deleteItem(u32 i);
+
 	// Adds an item to a suitable place. Returns leftover item.
 	// If all went into the list, returns NULL.
 	InventoryItem * addItem(InventoryItem *newitem);
@@ -445,6 +446,9 @@ public:
 	// If can be added fully, NULL is returned.
 	InventoryItem * addItem(u32 i, InventoryItem *newitem);
 
+	// Checks whether the item could be added to the given slot
+	bool itemFits(u32 i, InventoryItem *newitem);
+
 	// Takes some items from a slot.
 	// If there are not enough, takes as many as it can.
 	// Returns NULL if couldn't take any.
@@ -522,7 +526,7 @@ public:
 	*/
 	virtual Inventory* getInventory(InventoryContext *c, std::string id)
 		{return NULL;}
-	// Used on the server by InventoryAction::apply
+	// Used on the server by InventoryAction::apply and other stuff
 	virtual void inventoryModified(InventoryContext *c, std::string id)
 		{}
 	// Used on the client
@@ -600,5 +604,51 @@ struct IMoveAction : public InventoryAction
 	void apply(InventoryContext *c, InventoryManager *mgr);
 };
 
+/*
+	Craft checking system
+*/
+
+enum ItemSpecType
+{
+	ITEM_NONE,
+	ITEM_MATERIAL,
+	ITEM_CRAFT,
+	ITEM_TOOL,
+	ITEM_MBO
+};
+
+struct ItemSpec
+{
+	enum ItemSpecType type;
+	// Only other one of these is used
+	std::string name;
+	u16 num;
+
+	ItemSpec():
+		type(ITEM_NONE)
+	{
+	}
+	ItemSpec(enum ItemSpecType a_type, std::string a_name):
+		type(a_type),
+		name(a_name),
+		num(65535)
+	{
+	}
+	ItemSpec(enum ItemSpecType a_type, u16 a_num):
+		type(a_type),
+		name(""),
+		num(a_num)
+	{
+	}
+
+	bool checkItem(InventoryItem *item);
+};
+
+/*
+	items: a pointer to an array of 9 pointers to items
+	specs: a pointer to an array of 9 ItemSpecs
+*/
+bool checkItemCombination(InventoryItem **items, ItemSpec *specs);
+
 #endif
 
diff --git a/src/map.cpp b/src/map.cpp
index f6115a6..40274ae 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -1756,6 +1756,35 @@ void Map::removeNodeMetadata(v3s16 p)
 	block->m_node_metadata.remove(p_rel);
 }
 
+void Map::nodeMetadataStep(float dtime,
+		core::map<v3s16, MapBlock*> &changed_blocks)
+{
+	/*
+		NOTE:
+		Currently there is no way to ensure that all the necessary
+		blocks are loaded when this is run. (They might get unloaded)
+		NOTE: ^- Actually, that might not be so. In a quick test it
+		reloaded a block with a furnace when I walked back to it from
+		a distance.
+	*/
+	core::map<v2s16, MapSector*>::Iterator si;
+	si = m_sectors.getIterator();
+	for(; si.atEnd() == false; si++)
+	{
+		MapSector *sector = si.getNode()->getValue();
+		core::list< MapBlock * > sectorblocks;
+		sector->getBlocks(sectorblocks);
+		core::list< MapBlock * >::Iterator i;
+		for(i=sectorblocks.begin(); i!=sectorblocks.end(); i++)
+		{
+			MapBlock *block = *i;
+			bool changed = block->m_node_metadata.step(dtime);
+			if(changed)
+				changed_blocks[block->getPos()] = block;
+		}
+	}
+}
+
 /*
 	ServerMap
 */
diff --git a/src/map.h b/src/map.h
index b1b3b9a..081705a 100644
--- a/src/map.h
+++ b/src/map.h
@@ -285,6 +285,8 @@ public:
 	NodeMetadata* getNodeMetadata(v3s16 p);
 	void setNodeMetadata(v3s16 p, NodeMetadata *meta);
 	void removeNodeMetadata(v3s16 p);
+	void nodeMetadataStep(float dtime,
+			core::map<v3s16, MapBlock*> &changed_blocks);
 
 	/*
 		Variables
diff --git a/src/mapnode.cpp b/src/mapnode.cpp
index 8e968c8..187689c 100644
--- a/src/mapnode.cpp
+++ b/src/mapnode.cpp
@@ -25,6 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mineral.h"
 // For g_settings
 #include "main.h"
+#include "nodemetadata.h"
 
 ContentFeatures::~ContentFeatures()
 {
diff --git a/src/mapnode.h b/src/mapnode.h
index ce233e8..0423483 100644
--- a/src/mapnode.h
+++ b/src/mapnode.h
@@ -28,7 +28,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "serialization.h"
 #include "tile.h"
 #include "iirrlichtwrapper.h"
-#include "nodemetadata.h"
 
 /*
 	Initializes all kind of stuff in here.
@@ -121,6 +120,7 @@ enum LiquidType
 };
 
 class MapNode;
+class NodeMetadata;
 
 struct ContentFeatures
 {
diff --git a/src/nodemetadata.cpp b/src/nodemetadata.cpp
index 2405e76..21f55a0 100644
--- a/src/nodemetadata.cpp
+++ b/src/nodemetadata.cpp
@@ -178,6 +178,12 @@ FurnaceNodeMetadata::FurnaceNodeMetadata()
 	m_inventory->addList("fuel", 1);
 	m_inventory->addList("src", 1);
 	m_inventory->addList("dst", 1);
+
+	m_step_accumulator = 0;
+	m_fuel_totaltime = 0;
+	m_fuel_time = 0;
+	m_src_totaltime = 0;
+	m_src_time = 0;
 }
 FurnaceNodeMetadata::~FurnaceNodeMetadata()
 {
@@ -197,24 +203,134 @@ NodeMetadata* FurnaceNodeMetadata::create(std::istream &is)
 {
 	FurnaceNodeMetadata *d = new FurnaceNodeMetadata();
 	d->m_inventory->deSerialize(is);
-	/*std::string params;
-	std::getline(is, params, '\n');*/
+	int temp;
+	is>>temp;
+	d->m_fuel_totaltime = (float)temp/10;
+	is>>temp;
+	d->m_fuel_time = (float)temp/10;
 	return d;
 }
 void FurnaceNodeMetadata::serializeBody(std::ostream &os)
 {
 	m_inventory->serialize(os);
-	// This line will contain the other parameters
-	//os<<"\n";
+	os<<itos(m_fuel_totaltime*10)<<" ";
+	os<<itos(m_fuel_time*10)<<" ";
 }
 std::string FurnaceNodeMetadata::infoText()
 {
-	return "Furnace";
+	//return "Furnace";
+	if(m_fuel_time >= m_fuel_totaltime)
+	{
+		InventoryList *src_list = m_inventory->getList("src");
+		assert(src_list);
+		InventoryItem *src_item = src_list->getItem(0);
+
+		if(src_item)
+			return "Furnace is out of fuel";
+		else
+			return "Furnace is inactive";
+	}
+	else
+	{
+		std::string s = "Furnace is active (";
+		s += itos(m_fuel_time/m_fuel_totaltime*100);
+		s += "%)";
+		return s;
+	}
 }
 void FurnaceNodeMetadata::inventoryModified()
 {
 	dstream<<"Furnace inventory modification callback"<<std::endl;
 }
+bool FurnaceNodeMetadata::step(float dtime)
+{
+	// Update at a fixed frequency
+	const float interval = 0.5;
+	m_step_accumulator += dtime;
+	if(m_step_accumulator < interval)
+		return false;
+	m_step_accumulator -= interval;
+	dtime = interval;
+
+	//dstream<<"Furnace step dtime="<<dtime<<std::endl;
+	
+	InventoryList *dst_list = m_inventory->getList("dst");
+	assert(dst_list);
+
+	InventoryList *src_list = m_inventory->getList("src");
+	assert(src_list);
+	InventoryItem *src_item = src_list->getItem(0);
+
+	if(ItemSpec(ITEM_MATERIAL, CONTENT_TREE).checkItem(src_item)
+			&& dst_list->itemFits(0, new CraftItem("lump_of_coal", 1)))
+	{
+		m_src_totaltime = 3;
+	}
+	else
+	{
+		m_src_time = 0;
+		m_src_totaltime = 0;
+	}
+
+	if(m_fuel_time < m_fuel_totaltime)
+	{
+		//dstream<<"Furnace is active"<<std::endl;
+		m_fuel_time += dtime;
+		m_src_time += dtime;
+		if(m_src_time >= m_src_totaltime && m_src_totaltime > 0.001)
+		{
+			if(ItemSpec(ITEM_MATERIAL, CONTENT_TREE).checkItem(src_item))
+			{
+				src_list->decrementMaterials(1);
+				dst_list->addItem(0, new CraftItem("lump_of_coal", 1));
+				m_src_time = 0;
+				m_src_totaltime = 0;
+			}
+		}
+		return true;
+	}
+	
+	if(src_item == NULL || m_src_totaltime < 0.001)
+	{
+		return false;
+	}
+	
+	bool changed = false;
+
+	//dstream<<"Furnace is out of fuel"<<std::endl;
+
+	InventoryList *fuel_list = m_inventory->getList("fuel");
+	assert(fuel_list);
+	InventoryItem *fuel_item = fuel_list->getItem(0);
+
+	if(ItemSpec(ITEM_MATERIAL, CONTENT_TREE).checkItem(fuel_item))
+	{
+		m_fuel_totaltime = 10;
+		m_fuel_time = 0;
+		fuel_list->decrementMaterials(1);
+		changed = true;
+	}
+	else if(ItemSpec(ITEM_MATERIAL, CONTENT_WOOD).checkItem(fuel_item))
+	{
+		m_fuel_totaltime = 5;
+		m_fuel_time = 0;
+		fuel_list->decrementMaterials(1);
+		changed = true;
+	}
+	else if(ItemSpec(ITEM_CRAFT, "lump_of_coal").checkItem(fuel_item))
+	{
+		m_fuel_totaltime = 10;
+		m_fuel_time = 0;
+		fuel_list->decrementMaterials(1);
+		changed = true;
+	}
+	else
+	{
+		//dstream<<"No fuel found"<<std::endl;
+	}
+
+	return changed;
+}
 
 /*
 	NodeMetadatalist
@@ -318,3 +434,32 @@ void NodeMetadataList::set(v3s16 p, NodeMetadata *d)
 	m_data.insert(p, d);
 }
 
+bool NodeMetadataList::step(float dtime)
+{
+	bool something_changed = false;
+	for(core::map<v3s16, NodeMetadata*>::Iterator
+			i = m_data.getIterator();
+			i.atEnd()==false; i++)
+	{
+		v3s16 p = i.getNode()->getKey();
+		NodeMetadata *meta = i.getNode()->getValue();
+		bool changed = meta->step(dtime);
+		if(changed)
+			something_changed = true;
+		/*if(res.inventory_changed)
+		{
+			std::string inv_id;
+			inv_id += "nodemeta:";
+			inv_id += itos(p.X);
+			inv_id += ",";
+			inv_id += itos(p.Y);
+			inv_id += ",";
+			inv_id += itos(p.Z);
+			InventoryContext c;
+			c.current_player = NULL;
+			inv_mgr->inventoryModified(&c, inv_id);
+		}*/
+	}
+	return something_changed;
+}
+
diff --git a/src/nodemetadata.h b/src/nodemetadata.h
index e8aa576..c38ab13 100644
--- a/src/nodemetadata.h
+++ b/src/nodemetadata.h
@@ -59,6 +59,8 @@ public:
 	// This is called always after the inventory is modified, before
 	// the changes are copied elsewhere
 	virtual void inventoryModified(){}
+	// A step in time. Returns true if metadata changed.
+	virtual bool step(float dtime) {return false;}
 
 protected:
 	static void registerType(u16 id, Factory f);
@@ -115,15 +117,23 @@ public:
 	virtual std::string infoText();
 	virtual Inventory* getInventory() {return m_inventory;}
 	virtual void inventoryModified();
+	virtual bool step(float dtime);
 
 private:
 	Inventory *m_inventory;
+	float m_step_accumulator;
+	float m_fuel_totaltime;
+	float m_fuel_time;
+	float m_src_totaltime;
+	float m_src_time;
 };
 
 /*
 	List of metadata of all the nodes of a block
 */
 
+class InventoryManager;
+
 class NodeMetadataList
 {
 public:
@@ -138,6 +148,10 @@ public:
 	void remove(v3s16 p);
 	// Deletes old data and sets a new one
 	void set(v3s16 p, NodeMetadata *d);
+	
+	// A step in time. Returns true if something changed.
+	bool step(float dtime);
+
 private:
 	core::map<v3s16, NodeMetadata*> m_data;
 };
diff --git a/src/server.cpp b/src/server.cpp
index df712e0..c405af3 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -1503,6 +1503,32 @@ void Server::AsyncRunStep()
 		}
 	}
 	
+	/*
+		Step node metadata
+	*/
+	{
+		JMutexAutoLock envlock(m_env_mutex);
+		JMutexAutoLock conlock(m_con_mutex);
+		
+		core::map<v3s16, MapBlock*> changed_blocks;
+		m_env.getMap().nodeMetadataStep(dtime, changed_blocks);
+
+		for(core::map<v3s16, MapBlock*>::Iterator
+				i = changed_blocks.getIterator();
+				i.atEnd() == false; i++)
+		{
+			MapBlock *block = i.getNode()->getValue();
+
+			for(core::map<u16, RemoteClient*>::Iterator
+				i = m_clients.getIterator();
+				i.atEnd()==false; i++)
+			{
+				RemoteClient *client = i.getNode()->getValue();
+				client->SetBlockNotSent(block->getPos());
+			}
+		}
+	}
+		
 	/*
 		Trigger emergethread (it somehow gets to a non-triggered but
 		bysy state sometimes)
@@ -2740,7 +2766,6 @@ void Server::inventoryModified(InventoryContext *c, std::string id)
 		p.X = stoi(fn.next(","));
 		p.Y = stoi(fn.next(","));
 		p.Z = stoi(fn.next(","));
-		assert(c->current_player);
 		v3s16 blockpos = getNodeBlockPos(p);
 
 		NodeMetadata *meta = m_env.getMap().getNodeMetadata(p);
@@ -2888,163 +2913,6 @@ void Server::SendPlayerInfos()
 	m_con.SendToAll(0, data, true);
 }
 
-/*
-	Craft checking system
-*/
-
-enum ItemSpecType
-{
-	ITEM_NONE,
-	ITEM_MATERIAL,
-	ITEM_CRAFT,
-	ITEM_TOOL,
-	ITEM_MBO
-};
-
-struct ItemSpec
-{
-	ItemSpec():
-		type(ITEM_NONE)
-	{
-	}
-	ItemSpec(enum ItemSpecType a_type, std::string a_name):
-		type(a_type),
-		name(a_name),
-		num(65535)
-	{
-	}
-	ItemSpec(enum ItemSpecType a_type, u16 a_num):
-		type(a_type),
-		name(""),
-		num(a_num)
-	{
-	}
-	enum ItemSpecType type;
-	// Only other one of these is used
-	std::string name;
-	u16 num;
-};
-
-/*
-	items: a pointer to an array of 9 pointers to items
-	specs: a pointer to an array of 9 ItemSpecs
-*/
-bool checkItemCombination(InventoryItem **items, ItemSpec *specs)
-{
-	u16 items_min_x = 100;
-	u16 items_max_x = 100;
-	u16 items_min_y = 100;
-	u16 items_max_y = 100;
-	for(u16 y=0; y<3; y++)
-	for(u16 x=0; x<3; x++)
-	{
-		if(items[y*3 + x] == NULL)
-			continue;
-		if(items_min_x == 100 || x < items_min_x)
-			items_min_x = x;
-		if(items_min_y == 100 || y < items_min_y)
-			items_min_y = y;
-		if(items_max_x == 100 || x > items_max_x)
-			items_max_x = x;
-		if(items_max_y == 100 || y > items_max_y)
-			items_max_y = y;
-	}
-	// No items at all, just return false
-	if(items_min_x == 100)
-		return false;
-	
-	u16 items_w = items_max_x - items_min_x + 1;
-	u16 items_h = items_max_y - items_min_y + 1;
-
-	u16 specs_min_x = 100;
-	u16 specs_max_x = 100;
-	u16 specs_min_y = 100;
-	u16 specs_max_y = 100;
-	for(u16 y=0; y<3; y++)
-	for(u16 x=0; x<3; x++)
-	{
-		if(specs[y*3 + x].type == ITEM_NONE)
-			continue;
-		if(specs_min_x == 100 || x < specs_min_x)
-			specs_min_x = x;
-		if(specs_min_y == 100 || y < specs_min_y)
-			specs_min_y = y;
-		if(specs_max_x == 100 || x > specs_max_x)
-			specs_max_x = x;
-		if(specs_max_y == 100 || y > specs_max_y)
-			specs_max_y = y;
-	}
-	// No specs at all, just return false
-	if(specs_min_x == 100)
-		return false;
-
-	u16 specs_w = specs_max_x - specs_min_x + 1;
-	u16 specs_h = specs_max_y - specs_min_y + 1;
-
-	// Different sizes
-	if(items_w != specs_w || items_h != specs_h)
-		return false;
-
-	for(u16 y=0; y<specs_h; y++)
-	for(u16 x=0; x<specs_w; x++)
-	{
-		u16 items_x = items_min_x + x;
-		u16 items_y = items_min_y + y;
-		u16 specs_x = specs_min_x + x;
-		u16 specs_y = specs_min_y + y;
-		InventoryItem *item = items[items_y * 3 + items_x];
-		ItemSpec &spec = specs[specs_y * 3 + specs_x];
-		
-		if(spec.type == ITEM_NONE)
-		{
-			// Has to be no item
-			if(item != NULL)
-				return false;
-			continue;
-		}
-		
-		// There should be an item
-		if(item == NULL)
-			return false;
-
-		std::string itemname = item->getName();
-
-		if(spec.type == ITEM_MATERIAL)
-		{
-			if(itemname != "MaterialItem")
-				return false;
-			MaterialItem *mitem = (MaterialItem*)item;
-			if(mitem->getMaterial() != spec.num)
-				return false;
-		}
-		else if(spec.type == ITEM_CRAFT)
-		{
-			if(itemname != "CraftItem")
-				return false;
-			CraftItem *mitem = (CraftItem*)item;
-			if(mitem->getSubName() != spec.name)
-				return false;
-		}
-		else if(spec.type == ITEM_TOOL)
-		{
-			// Not supported yet
-			assert(0);
-		}
-		else if(spec.type == ITEM_MBO)
-		{
-			// Not supported yet
-			assert(0);
-		}
-		else
-		{
-			// Not supported yet
-			assert(0);
-		}
-	}
-
-	return true;
-}
-
 void Server::SendInventory(u16 peer_id)
 {
 	DSTACK(__FUNCTION_NAME);