diff --git a/birdvisu/visualisation.py b/birdvisu/visualisation.py
new file mode 100644
index 0000000..a50415f
--- /dev/null
+++ b/birdvisu/visualisation.py
@@ -0,0 +1,133 @@
+from birdvisu.maps import Topology, TopologyDifference
+
+from PySide6 import QtCore, QtGui, QtWidgets
+
+from dataclasses import dataclass
+from enum import Enum, auto
+
+class NodeType(Enum):
+	ROUTER = auto()
+	NETWORK = auto()
+
+class NodeStatus(Enum):
+	NORMAL = auto()
+	MISSING = auto()
+	EXTRA = auto()
+	DISCREPANCY = auto()
+
+@dataclass
+class VisualisationNode:
+	position: tuple[float, float]
+	type: NodeType
+	status: NodeStatus
+	details: tuple[str, list]
+
+	def draw_on_scene(self, scene):
+		# FIXME: Allow different styles
+		# TODO: not everything is a QRectF…
+		x, y = self.position
+		fill = QtGui.QBrush(QtGui.QColor(
+			{
+				# Poor man's switch
+				# Py 3.10 might be too new and this is probably more compact still.
+				NodeStatus.NORMAL: 'black',
+				NodeStatus.MISSING: 'red',
+				NodeStatus.EXTRA: 'green',
+				NodeStatus.DISCREPANCY: 'blue',
+				}[self.status]
+			))
+		w, h = {
+			NodeType.ROUTER: (40, 40),
+			NodeType.NETWORK: (10, 10),
+			}[self.type]
+		return scene.addRect(
+			QtCore.QRectF(x, y, w, h),
+			brush = fill,
+			)
+		
+
+
+def nodes_from_topodiff(topodiff, visu_style='default') -> list[VisualisationNode]:
+	result = []
+
+	def get_node(dir_tuple, type):
+		n, nd = dir_tuple
+		visu_details = list(filter(lambda x: x[0] == ('visualisation '+visu_style), nd))
+		if len(visu_details) > 1:
+			visu_details = visu_details[0][1]
+			det_dict = {}
+			for det in visu_details:
+				k, v = det.split(' ', maxxplit=1)
+				det_dict[k] = v
+			pos = det_dict['position']
+			x, y = map(float, pos.strip('[]').split())
+		else:
+			# Probably an extra node
+			# TODO: proper automatic placement
+			import random
+			x = random.randint(0, 2000) # FIXME: dimensions?
+			y = random.randint(0, 2000)
+		return VisualisationNode(
+			position = (x, y),
+			type = type,
+			status = NodeStatus.NORMAL, # Will change in a while
+			details = dir_tuple,
+			)
+	
+	for r in topodiff.reference.routers:
+		node = get_node(r, type=NodeType.ROUTER)
+		if r[0] in topodiff.routers_missing:
+			node.status = NodeStatus.MISSING
+		result.append(node)
+
+	for n in topodiff.reference.networks:
+		node = get_node(n, type=NodeType.NETWORK)
+		if n[0] in topodiff.networks_missing:
+			node.status = NodeStatus.MISSING
+		result.append(node)
+
+	for r in topodiff.actual.routers:
+		if r[0] in topodiff.routers_extra:
+			node = get_node(r, type=NodeType.ROUTER)
+			node.status = NodeStatus.EXTRA
+			result.append(node)
+
+	for n in topodiff.actual.networks:
+		if n[0] in topodiff.networks_extra:
+			node = get_node(n, type=NodeType.NETWORK)
+			node.status = NodeStatus.EXTRA
+			result.append(node)
+	
+	return result
+	
+
+class Visualisation(QtWidgets.QWidget):
+	def __init__(self, topodiff=None):
+		super().__init__()
+
+		# guard:
+		self.scene = None
+		self.view = None
+		self.topodiff = None
+		self.items_nodes = None
+		self.items_edges = None
+
+		if topodiff is not None:
+			self.set_topology_difference(topodiff)
+
+	def set_topology_difference(self, topodiff):
+		self.topodiff = topodiff
+		self.draw_scene()
+
+	def draw_scene(self):
+		self.scene = QtWidgets.QGraphicsScene(self)
+		self.view = QtWidgets.QGraphicsView(self.scene)
+
+		if self.topodiff is not None:
+			nodes = nodes_from_topodiff(self.topodiff)
+			# TODO: filtering (dependent on UI)
+			if self.items_nodes is None:
+				self.items_nodes = {} # dict: ident -> QGraphicsItem
+			for n in nodes:
+				assert n.details[0] not in self.items_nodes, f'{n.details} already in dictionary'
+				self.items_nodes[n.details[0]] = n.draw_on_scene(self.scene)