diff --git a/__init__.py b/__init__.py
index 07b3ea7..e69de29 100644
--- a/__init__.py
+++ b/__init__.py
@@ -1,57 +0,0 @@
-from dataclasses import dataclass, field
-from typing import Any, Iterator, Protocol
-
-type Entity = int
-type Archetype = frozenset[type]
-type ComponentMap = dict[type, Any]
-type EntityComponentStorage = dict[Entity, ComponentMap]
-
-
-class System(Protocol):
-    @classmethod
-    def process(cls, world: "World") -> None: ...
-
-
-@dataclass
-class World:
-    registry: dict[Archetype, EntityComponentStorage] = field(default_factory=dict)
-    next_entity_index: int = 0
-    systems: list[type[System]] = field(default_factory=list)
-
-    def generate_id(self) -> int:
-        self.next_entity_index += 1
-        return self.next_entity_index
-
-    def spawn(self, *components) -> int:
-        archetype = frozenset([type(c) for c in components])
-
-        if archetype not in self.registry:
-            self.registry[archetype] = {}
-
-        entity = self.generate_id()
-        self.registry[archetype][entity] = {type(c): c for c in components}
-        return entity
-
-    def query(
-        self, *component_types, exact=False
-    ) -> Iterator[tuple[Entity, ComponentMap]]:
-        component_subset_signature = frozenset(component_types)
-        for archetype, entity_component_storage in self.registry.items():
-            if (exact and component_subset_signature == archetype) or (
-                not exact and component_subset_signature.issubset(archetype)
-            ):
-                for entity, component_storage in entity_component_storage.items():
-                    yield entity, component_storage
-
-    def get_components(self, entity: int, pop=False):
-        for componentstorage in self.registry.values():
-            if entity in componentstorage:
-                if pop:
-                    return componentstorage.pop(entity, None)
-                else:
-                    return componentstorage[entity]
-        return None
-
-    def tick(self, *args, **kwargs):
-        for system in self.systems:
-            system.process(self, *args, **kwargs)
diff --git a/event.py b/event.py
new file mode 100644
index 0000000..4b6ff37
--- /dev/null
+++ b/event.py
@@ -0,0 +1,9 @@
+class EventBus:
+    def __init__(self):
+        self.events = []
+
+    def publish(self, event):
+        self.events.append(event)
+
+    def pop(self):
+        return self.events.pop(0)
diff --git a/system.py b/system.py
new file mode 100644
index 0000000..bf844a3
--- /dev/null
+++ b/system.py
@@ -0,0 +1,7 @@
+from __future__ import annotations
+from typing import Protocol
+
+
+class System(Protocol):
+    @classmethod
+    def process(cls, world, *args, **kwargs) -> None: ...
diff --git a/world.py b/world.py
new file mode 100644
index 0000000..c983345
--- /dev/null
+++ b/world.py
@@ -0,0 +1,54 @@
+from dataclasses import dataclass, field
+from typing import Any, Iterator
+
+from .system import System
+
+type Entity = int
+type Archetype = frozenset[type]
+type ComponentMap = dict[type, Any]
+type EntityComponentStorage = dict[Entity, ComponentMap]
+
+
+@dataclass
+class World:
+    registry: dict[Archetype, EntityComponentStorage] = field(default_factory=dict)
+    next_entity_index: int = 0
+    systems: list[type[System]] = field(default_factory=list)
+
+    def generate_id(self) -> int:
+        self.next_entity_index += 1
+        return self.next_entity_index
+
+    def spawn(self, *components) -> int:
+        archetype = frozenset([type(c) for c in components])
+
+        if archetype not in self.registry:
+            self.registry[archetype] = {}
+
+        entity = self.generate_id()
+        self.registry[archetype][entity] = {type(c): c for c in components}
+        return entity
+
+    def query(
+        self, *component_types, exact=False
+    ) -> Iterator[tuple[Entity, ComponentMap]]:
+        component_subset_signature = frozenset(component_types)
+        for archetype, entity_component_storage in self.registry.items():
+            if (exact and component_subset_signature == archetype) or (
+                not exact and component_subset_signature.issubset(archetype)
+            ):
+                for entity, component_storage in entity_component_storage.items():
+                    yield entity, component_storage
+
+    def get_components(self, entity: int, pop=False):
+        for componentstorage in self.registry.values():
+            if entity in componentstorage:
+                if pop:
+                    return componentstorage.pop(entity, None)
+                else:
+                    return componentstorage[entity]
+        return None
+
+    def tick(self, *args, **kwargs):
+        for system in self.systems:
+            system.process(self, *args, **kwargs)