diff --git a/SDK/include/NDK/Algorithm.hpp b/SDK/include/NDK/Algorithm.hpp
new file mode 100644
index 000000000..68d4711d4
--- /dev/null
+++ b/SDK/include/NDK/Algorithm.hpp
@@ -0,0 +1,20 @@
+// Copyright (C) 2015 Jérôme Leclercq
+// This file is part of the "Nazara Development Kit"
+// For conditions of distribution and use, see copyright notice in Prerequesites.hpp
+
+#pragma once
+
+#ifndef NDK_ALGORITHM_HPP
+#define NDK_ALGORITHM_HPP
+
+#include <NDK/Prerequesites.hpp>
+
+namespace Ndk
+{
+	template<unsigned int N> ComponentId BuildComponentId(const char (&id)[N]);
+	template<typename ComponentType> constexpr ComponentId GetComponentId();
+}
+
+#include <Ndk/Algorithm.inl>
+
+#endif // NDK_ALGORITHM_HPP
diff --git a/SDK/include/NDK/Algorithm.inl b/SDK/include/NDK/Algorithm.inl
new file mode 100644
index 000000000..dbe2b292d
--- /dev/null
+++ b/SDK/include/NDK/Algorithm.inl
@@ -0,0 +1,27 @@
+// Copyright (C) 2015 Jérôme Leclercq
+// This file is part of the "Nazara Development Kit"
+// For conditions of distribution and use, see copyright notice in Prerequesites.hpp
+
+#include <Nazara/Core/Endianness.hpp>
+
+namespace Ndk
+{
+	///TODO: constexpr avec le C++14
+	template<unsigned int N>
+	ComponentId BuildComponentId(const char (&id)[N])
+	{
+		static_assert(N-1 <= sizeof(ComponentId), "ID too long for this size of component id");
+
+		ComponentId componentId = 0;
+		for (int i = 0; i < N; ++i)
+			componentId |= static_cast<ComponentId>(id[i]) << i*8;
+
+		return componentId;
+	}
+
+	template<typename ComponentType>
+	constexpr ComponentId GetComponentId()
+	{
+		return ComponentType::ComponentId;
+	}
+}
diff --git a/SDK/include/NDK/BaseComponent.hpp b/SDK/include/NDK/BaseComponent.hpp
index a3a4a08fb..a77514d64 100644
--- a/SDK/include/NDK/BaseComponent.hpp
+++ b/SDK/include/NDK/BaseComponent.hpp
@@ -14,20 +14,15 @@ namespace Ndk
 	class NDK_API BaseComponent
 	{
 		public:
-			BaseComponent(nzUInt32 componentId);
+			BaseComponent(ComponentId componentId);
 			virtual ~BaseComponent();
 
 			virtual BaseComponent* Clone() const = 0;
 
-			nzUInt32 GetId() const;
-
-			static nzUInt32 GetNextId();
+			ComponentId GetId() const;
 
 		protected:
-			nzUInt32 m_componentId;
-
-		private:
-			static nzUInt32 s_nextId;
+			ComponentId m_componentId;
 	};
 }
 
diff --git a/SDK/include/NDK/BaseComponent.inl b/SDK/include/NDK/BaseComponent.inl
index cea669f60..f0262f042 100644
--- a/SDK/include/NDK/BaseComponent.inl
+++ b/SDK/include/NDK/BaseComponent.inl
@@ -4,18 +4,13 @@
 
 namespace Ndk
 {
-	inline BaseComponent::BaseComponent(nzUInt32 componentId) :
+	inline BaseComponent::BaseComponent(ComponentId componentId) :
 	m_componentId(componentId)
 	{
 	}
 
-	inline nzUInt32 BaseComponent::GetId() const
+	inline ComponentId BaseComponent::GetId() const
 	{
 		return m_componentId;
 	}
-
-	inline nzUInt32 BaseComponent::GetNextId()
-	{
-		return s_nextId++;
-	}
 }
diff --git a/SDK/include/NDK/Component.hpp b/SDK/include/NDK/Component.hpp
index d1b96d279..09f23a281 100644
--- a/SDK/include/NDK/Component.hpp
+++ b/SDK/include/NDK/Component.hpp
@@ -20,8 +20,6 @@ namespace Ndk
 
 			BaseComponent* Clone() const override;
 	};
-
-	template<typename ComponentType> constexpr nzUInt32 GetComponentId();
 }
 
 #include <NDK/Component.inl>
diff --git a/SDK/include/NDK/Component.inl b/SDK/include/NDK/Component.inl
index 357c7f594..4a860dfd7 100644
--- a/SDK/include/NDK/Component.inl
+++ b/SDK/include/NDK/Component.inl
@@ -2,6 +2,7 @@
 // This file is part of the "Nazara Development Kit"
 // For conditions of distribution and use, see copyright notice in Prerequesites.hpp
 
+#include <Ndk/Algorithm.hpp>
 #include <type_traits>
 
 namespace Ndk
@@ -23,10 +24,4 @@ namespace Ndk
 
 		return new ComponentType(static_cast<const ComponentType&>(*this));
 	}
-
-	template<typename ComponentType>
-	constexpr nzUInt32 GetComponentId()
-	{
-		return ComponentType::ComponentId;
-	}
 }
diff --git a/SDK/include/NDK/Entity.hpp b/SDK/include/NDK/Entity.hpp
index 28e539d93..d15c46625 100644
--- a/SDK/include/NDK/Entity.hpp
+++ b/SDK/include/NDK/Entity.hpp
@@ -11,6 +11,7 @@
 #include <NDK/Component.hpp>
 #include <memory>
 #include <vector>
+#include <unordered_map>
 
 namespace Ndk
 {
@@ -23,8 +24,6 @@ namespace Ndk
 		friend World;
 
 		public:
-			using Id = nzUInt32;
-
 			Entity(const Entity&) = delete;
 			Entity(Entity&& entity);
 			~Entity();
@@ -34,13 +33,12 @@ namespace Ndk
 
 			EntityHandle CreateHandle();
 
-			BaseComponent& GetComponent(nzUInt32 componentId);
+			BaseComponent& GetComponent(ComponentId componentId);
 			template<typename ComponentType> ComponentType& GetComponent();
-			const NzBitset<>& GetComponentBits() const;
-			Id GetId() const;
+			EntityId GetId() const;
 			World* GetWorld() const;
 
-			bool HasComponent(nzUInt32 componentId) const;
+			bool HasComponent(ComponentId componentId) const;
 			template<typename ComponentType> bool HasComponent() const;
 
 			void Kill();
@@ -48,14 +46,14 @@ namespace Ndk
 			bool IsValid() const;
 
 			void RemoveAllComponents();
-			void RemoveComponent(nzUInt32 componentId);
+			void RemoveComponent(ComponentId componentId);
 			template<typename ComponentType> void RemoveComponent();
 
 			Entity& operator=(const Entity&) = delete;
 			Entity& operator=(Entity&&) = delete;
 
 		private:
-			Entity(World& world, Id id);
+			Entity(World& world, EntityId id);
 
 			void Create();
 			void Destroy();
@@ -63,10 +61,9 @@ namespace Ndk
 			void RegisterHandle(EntityHandle* handle);
 			void UnregisterHandle(EntityHandle* handle);
 
-			std::vector<std::unique_ptr<BaseComponent>> m_components;
 			std::vector<EntityHandle*> m_handles;
-			Id m_id;
-			NzBitset<> m_componentBits;
+			std::unordered_map<ComponentId, std::unique_ptr<BaseComponent>> m_components;
+			EntityId m_id;
 			World* m_world;
 			bool m_valid;
 	};
diff --git a/SDK/include/NDK/Entity.inl b/SDK/include/NDK/Entity.inl
index 3dbe0d65f..0f6489b24 100644
--- a/SDK/include/NDK/Entity.inl
+++ b/SDK/include/NDK/Entity.inl
@@ -9,7 +9,7 @@
 
 namespace Ndk
 {
-	inline Entity::Entity(World& world, Id id) :
+	inline Entity::Entity(World& world, EntityId id) :
 	m_id(id),
 	m_world(&world)
 	{
@@ -25,7 +25,7 @@ namespace Ndk
 		return static_cast<ComponentType&>(AddComponent(std::move(ptr)));
 	}
 
-	inline BaseComponent& Entity::GetComponent(nzUInt32 componentId)
+	inline BaseComponent& Entity::GetComponent(ComponentId componentId)
 	{
 		///DOC: Le component doit être présent
 		NazaraAssert(HasComponent(componentId), "This component is not part of the entity");
@@ -42,16 +42,11 @@ namespace Ndk
 		///DOC: Le component doit être présent
 		static_assert(std::is_base_of<BaseComponent, ComponentType>(), "ComponentType is not a component");
 
-		nzUInt32 componentId = GetComponentId<ComponentType>();
+		ComponentId componentId = GetComponentId<ComponentType>();
 		return static_cast<ComponentType&>(GetComponent(componentId));
 	}
 
-	inline const NzBitset<>& Entity::GetComponentBits() const
-	{
-		return m_componentBits;
-	}
-
-	inline Entity::Id Entity::GetId() const
+	inline EntityId Entity::GetId() const
 	{
 		return m_id;
 	}
@@ -61,9 +56,9 @@ namespace Ndk
 		return m_world;
 	}
 
-	inline bool Entity::HasComponent(nzUInt32 componentId) const
+	inline bool Entity::HasComponent(ComponentId componentId) const
 	{
-		return m_components.size() > componentId && m_components[componentId];
+		return m_components.count(componentId) > 0;
 	}
 
 	template<typename ComponentType>
@@ -71,7 +66,7 @@ namespace Ndk
 	{
 		static_assert(std::is_base_of<BaseComponent, ComponentType>(), "ComponentType is not a component");
 
-		nzUInt32 componentId = GetComponentId<ComponentType>();
+		ComponentId componentId = GetComponentId<ComponentType>();
 		return HasComponent(componentId);
 	}
 
@@ -80,7 +75,7 @@ namespace Ndk
 	{
 		static_assert(std::is_base_of<BaseComponent, ComponentType>(), "ComponentType is not a component");
 
-		nzUInt32 componentId = GetComponentId<ComponentType>();
+		ComponentId componentId = GetComponentId<ComponentType>();
 		RemoveComponent(componentId);
 	}
 
diff --git a/SDK/include/NDK/Prerequesites.hpp b/SDK/include/NDK/Prerequesites.hpp
index d42c75dc0..f83ef5506 100644
--- a/SDK/include/NDK/Prerequesites.hpp
+++ b/SDK/include/NDK/Prerequesites.hpp
@@ -55,4 +55,10 @@
 	#define NDK_API
 #endif
 
+namespace Ndk
+{
+	using ComponentId = nzUInt32;
+	using EntityId = nzUInt32;
+}
+
 #endif // NDK_PREREQUESITES_HPP
diff --git a/SDK/include/NDK/World.hpp b/SDK/include/NDK/World.hpp
index 41fab8989..6b21469dc 100644
--- a/SDK/include/NDK/World.hpp
+++ b/SDK/include/NDK/World.hpp
@@ -29,13 +29,13 @@ namespace Ndk
 
 			void Clear();
 
-			const EntityHandle& GetEntity(Entity::Id id);
+			const EntityHandle& GetEntity(EntityId id);
 
 			void KillEntity(const EntityHandle& entity);
 			void KillEntities(const EntityList& list);
 
 			bool IsEntityValid(const EntityHandle& entity) const;
-			bool IsEntityIdValid(Entity::Id id) const;
+			bool IsEntityIdValid(EntityId id) const;
 
 			void Update();
 
@@ -51,7 +51,7 @@ namespace Ndk
 				unsigned int aliveIndex;
 			};
 
-			std::vector<Entity::Id> m_freeIdList;
+			std::vector<EntityId> m_freeIdList;
 			std::vector<EntityBlock> m_entities;
 			EntityList m_aliveEntities;
 			NzBitset<nzUInt64> m_killedEntities;
diff --git a/SDK/include/NDK/World.inl b/SDK/include/NDK/World.inl
index c252f5e57..7ecc6d0ae 100644
--- a/SDK/include/NDK/World.inl
+++ b/SDK/include/NDK/World.inl
@@ -28,7 +28,7 @@ namespace Ndk
 		return entity.IsValid() && entity->GetWorld() == this && IsEntityIdValid(entity->GetId());
 	}
 
-	inline bool World::IsEntityIdValid(Entity::Id id) const
+	inline bool World::IsEntityIdValid(EntityId id) const
 	{
 		return id < m_entities.size() && m_entities[id].entity.IsValid();
 	}
diff --git a/SDK/src/NDK/BaseComponent.cpp b/SDK/src/NDK/BaseComponent.cpp
index f3bbaaa19..f227f40a0 100644
--- a/SDK/src/NDK/BaseComponent.cpp
+++ b/SDK/src/NDK/BaseComponent.cpp
@@ -7,6 +7,4 @@
 namespace Ndk
 {
 	BaseComponent::~BaseComponent() = default;
-
-	nzUInt32 BaseComponent::s_nextId = 0;
 }
diff --git a/SDK/src/NDK/Entity.cpp b/SDK/src/NDK/Entity.cpp
index c84ec83c7..e3e499f6a 100644
--- a/SDK/src/NDK/Entity.cpp
+++ b/SDK/src/NDK/Entity.cpp
@@ -27,18 +27,10 @@ namespace Ndk
 	{
 		NazaraAssert(component, "Component must be valid");
 
-		nzUInt32 componentId = component->GetId();
-
-		// Nous supprimons l'ancien component, s'il existe
-		RemoveComponent(componentId);
-
-		// Nous nous assurons que le vecteur de component est suffisamment grand pour contenir le nouveau component
-		if (m_components.size() <= componentId)
-			m_components.resize(componentId + 1);
+		ComponentId componentId = component->GetId();
 
 		// Affectation et retour du component
 		m_components[componentId] = std::move(component);
-		m_componentBits.UnboundedSet(componentId);
 
 		return *m_components[componentId].get();
 	}
@@ -61,17 +53,13 @@ namespace Ndk
 	void Entity::RemoveAllComponents()
 	{
 		m_components.clear();
-		m_componentBits.Clear();
 	}
 
-	void Entity::RemoveComponent(nzUInt32 componentId)
+	void Entity::RemoveComponent(ComponentId componentId)
 	{
 		///DOC: N'a aucun effet si le component n'est pas présent
 		if (HasComponent(componentId))
-		{
 			m_components[componentId].reset();
-			m_componentBits.Reset(componentId);
-		}
 	}
 
 	void Entity::Create()
diff --git a/SDK/src/NDK/World.cpp b/SDK/src/NDK/World.cpp
index 7e2984de5..a04c1f4d2 100644
--- a/SDK/src/NDK/World.cpp
+++ b/SDK/src/NDK/World.cpp
@@ -15,7 +15,7 @@ namespace Ndk
 
 	EntityHandle World::CreateEntity()
 	{
-		Entity::Id id;
+		EntityId id;
 		if (!m_freeIdList.empty())
 		{
 			// On récupère un identifiant
@@ -62,7 +62,7 @@ namespace Ndk
 			m_killedEntities.UnboundedSet(entity->GetId(), true);
 	}
 
-	const EntityHandle& World::GetEntity(Entity::Id id)
+	const EntityHandle& World::GetEntity(EntityId id)
 	{
 		if (IsEntityIdValid(id))
 			return m_aliveEntities[m_entities[id].aliveIndex];