diff --git a/src/main/java/net/onrc/onos/registry/controller/IControllerRegistryService.java b/src/main/java/net/onrc/onos/registry/controller/IControllerRegistryService.java
new file mode 100644
index 0000000..f2794cc
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/IControllerRegistryService.java
@@ -0,0 +1,48 @@
+package net.onrc.onos.registry.controller;
+
+import java.util.Collection;
+import java.util.Map;
+
+import net.floodlightcontroller.core.module.IFloodlightService;
+
+public interface IControllerRegistryService extends IFloodlightService {
+	
+	// Callback for all mastership changes. 
+	// Change callback is called when mastership is acquired or released
+	public interface ControlChangeCallback {
+		public void controlChanged(long dpid, boolean hasControl);
+	}
+	
+	// Acquire mastership for a switch. 
+	public void requestControl(long dpid, ControlChangeCallback cb) throws Exception;
+	
+	// Release mastership for a switch
+	public void releaseControl(long dpid);
+	
+	// Check if I am the master of a switch. This is a nonblocking call that checks if the caller is a 
+	public boolean hasControl(long dpid);
+	
+	// Set/Get mastership identifier.
+	// This is typically a unique identifier of the controller that does not change across restarts
+	public void setMastershipId (String id);
+	public String getMastershipId ();
+	
+	/**
+	 * Register a controller to the ONOS cluster
+	 * @param controller A string identifying the controller
+	 */
+	public void registerController(String controllerId) throws RegistryException;
+	
+	/**
+	 * Get all controllers in the cluster
+	 * @return
+	 */
+	public Collection<String> getAllControllers() throws RegistryException;
+	
+	
+	public String getControllerForSwitch(long dpid) throws RegistryException;
+	
+	public Collection<Map<String, String>> getAllSwitches();
+	
+	public Collection<Long> getSwitchesControlledByController(String controllerId);
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/IMastershipHelper.java b/src/main/java/net/onrc/onos/registry/controller/IMastershipHelper.java
new file mode 100644
index 0000000..9e07d46
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/IMastershipHelper.java
@@ -0,0 +1,27 @@
+package net.onrc.onos.registry.controller;
+
+public interface IMastershipHelper {
+	
+	// Callback for all mastership changes. 
+	// Change callback is called when mastership is acquired or released
+	public interface MastershipCallback {
+		public void changeCallback(long dpid);
+	}
+	
+	// Set/get mastership identifier. This is used to set the unique identifier of the controller that is asking for mastership.
+	// It needs to be set first before any mastership call can be made
+	public void setMastershipId (String id);
+	public String getMastershipId ();
+	
+	// Request mastership for a switch. Our request for mastership remains in a queue. If we win mastership, the callback
+	// is called. This call is non-blocking and can be called from the packet processing context as well.
+	public void requestMastership(long dpid, MastershipCallback cb);
+	
+	// Release mastership for a switch. If we are the master, then the mastership will be released and given to the next
+	// controller who had requested mastership. If we are not the master our request for mastership will be 
+	// removed from the queue.
+	public void releaseMastership(long dpid);
+	
+	// Check if I am the master of a switch and return true if I am the master. 
+	public boolean amMaster(long dpid);	
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/MastershipHelper.java b/src/main/java/net/onrc/onos/registry/controller/MastershipHelper.java
new file mode 100644
index 0000000..2fcd002
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/MastershipHelper.java
@@ -0,0 +1,35 @@
+package net.onrc.onos.registry.controller;
+
+public class MastershipHelper implements IMastershipHelper {
+
+	@Override
+	public void setMastershipId(String id) {
+		// TODO Auto-generated method stub
+
+	}
+
+	@Override
+	public String getMastershipId() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	@Override
+	public void requestMastership(long dpid, MastershipCallback cb) {
+		// TODO Auto-generated method stub
+		return;
+	}
+
+	@Override
+	public void releaseMastership(long dpid) {
+		// TODO Auto-generated method stub
+
+	}
+
+	@Override
+	public boolean amMaster(long dpid) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/RegistryException.java b/src/main/java/net/onrc/onos/registry/controller/RegistryException.java
new file mode 100644
index 0000000..3b237c2
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/RegistryException.java
@@ -0,0 +1,28 @@
+package net.onrc.onos.registry.controller;
+
+public class RegistryException extends Exception {
+
+	private static final long serialVersionUID = -8276300722010217913L;
+	
+	/*
+	public RegistryException() {
+		// TODO Auto-generated constructor stub
+	}
+
+	
+	public RegistryException(String message) {
+		super(message);
+		// TODO Auto-generated constructor stub
+	}
+
+	public RegistryException(Throwable cause) {
+		super(cause);
+		// TODO Auto-generated constructor stub
+	}
+	*/
+	
+	public RegistryException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/RegistryManager.java b/src/main/java/net/onrc/onos/registry/controller/RegistryManager.java
new file mode 100644
index 0000000..84f17c3
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/RegistryManager.java
@@ -0,0 +1,359 @@
+package net.onrc.onos.registry.controller;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import net.floodlightcontroller.core.module.FloodlightModuleContext;
+import net.floodlightcontroller.core.module.FloodlightModuleException;
+import net.floodlightcontroller.core.module.IFloodlightModule;
+import net.floodlightcontroller.core.module.IFloodlightService;
+
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.WatchedEvent;
+import org.apache.zookeeper.Watcher.Event.KeeperState;
+import org.openflow.util.HexString;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.netflix.curator.RetryPolicy;
+import com.netflix.curator.framework.CuratorFramework;
+import com.netflix.curator.framework.CuratorFrameworkFactory;
+import com.netflix.curator.framework.api.CuratorWatcher;
+import com.netflix.curator.framework.recipes.cache.ChildData;
+import com.netflix.curator.framework.recipes.cache.PathChildrenCache;
+import com.netflix.curator.framework.recipes.cache.PathChildrenCache.StartMode;
+import com.netflix.curator.framework.recipes.leader.LeaderLatch;
+import com.netflix.curator.framework.recipes.leader.Participant;
+import com.netflix.curator.retry.RetryOneTime;
+
+public class RegistryManager implements IFloodlightModule, IControllerRegistryService {
+
+	protected static Logger log = LoggerFactory.getLogger(RegistryManager.class);
+	protected String mastershipId = null;
+	
+	//TODO read this from configuration
+	protected String connectionString = "localhost:2181";
+	private final String namespace = "onos";
+	private final String switchLatchesPath = "/switches";
+	
+	protected CuratorFramework client;
+	
+	private final String controllerPath = "/controllers";
+	protected PathChildrenCache controllerCache;
+
+	protected Map<String, LeaderLatch> switchLatches;
+	protected Map<String, ControlChangeCallback> switchCallbacks;
+	
+	protected boolean moduleEnabled = false;
+	
+	protected class ParamaterizedCuratorWatcher implements CuratorWatcher {
+		private String dpid;
+		private boolean isLeader = false;
+		private String latchPath;
+		
+		public ParamaterizedCuratorWatcher(String dpid, String latchPath){
+			this.dpid = dpid;
+			this.latchPath = latchPath;
+		}
+		
+		@Override
+		public synchronized void process(WatchedEvent event) throws Exception {
+			log.debug("Watch Event: {}", event);
+
+			LeaderLatch latch = switchLatches.get(dpid);
+			
+			if (event.getState() == KeeperState.Disconnected){
+				if (isLeader) {
+					log.debug("Disconnected while leader - lost leadership for {}", dpid);
+					
+					isLeader = false;
+					switchCallbacks.get(dpid).controlChanged(HexString.toLong(dpid), false);
+				}
+				return;
+			}
+			
+			try {
+				
+				Participant leader = latch.getLeader();
+
+				if (leader.getId().equals(mastershipId) && !isLeader){
+					log.debug("Became leader for {}", dpid);
+					
+					isLeader = true;
+					switchCallbacks.get(dpid).controlChanged(HexString.toLong(dpid), true);
+				}
+				else if (!leader.getId().equals(mastershipId) && isLeader){
+					log.debug("Lost leadership for {}", dpid);
+					
+					isLeader = false;
+					switchCallbacks.get(dpid).controlChanged(HexString.toLong(dpid), false);
+				}
+			} catch (Exception e){
+				if (isLeader){
+					log.debug("Exception checking leadership status. Assume leadship lost for {}",
+							dpid);
+					
+					isLeader = false;
+					switchCallbacks.get(dpid).controlChanged(HexString.toLong(dpid), false);
+				}
+			}
+			
+			client.getChildren().usingWatcher(this).inBackground().forPath(latchPath);
+			//client.getChildren().usingWatcher(this).forPath(latchPath);
+		}
+	}
+
+	
+	@Override
+	public void requestControl(long dpid, ControlChangeCallback cb) throws Exception {
+		
+		if (!moduleEnabled) return;
+		
+		if (mastershipId == null){
+			throw new RuntimeException("Must set mastershipId before calling aquireMastership");
+		}
+		
+		String dpidStr = HexString.toHexString(dpid);
+		String latchPath = switchLatchesPath + "/" + dpidStr;
+		
+		if (switchLatches.get(dpidStr) != null){
+			throw new RuntimeException("Leader election for switch " + dpidStr +
+					"is already running");
+		}
+		
+		LeaderLatch latch = new LeaderLatch(client, latchPath, mastershipId);
+		switchLatches.put(dpidStr, latch);
+		switchCallbacks.put(dpidStr, cb);
+		
+		try {
+			//client.getChildren().usingWatcher(watcher).inBackground().forPath(singleLatchPath);
+			client.getChildren().usingWatcher(
+					new ParamaterizedCuratorWatcher(dpidStr, latchPath))
+					.inBackground().forPath(latchPath);
+			latch.start();
+		} catch (Exception e) {
+			log.warn("Error starting leader latch: {}", e.getMessage());
+			throw e;
+		}
+		
+	}
+
+	@Override
+	public void releaseControl(long dpid) {
+		if (!moduleEnabled) return;
+		
+		String dpidStr = HexString.toHexString(dpid);
+		
+		LeaderLatch latch = switchLatches.get(dpidStr);
+		if (latch == null) {
+			log.debug("Trying to release mastership for switch we are not contesting");
+			return;
+		}
+		
+		try {
+			latch.close();
+		} catch (IOException e) {
+			//I think it's OK not to do anything here. Either the node got deleted correctly,
+			//or the connection went down and the node got deleted.
+		} finally {
+			switchLatches.remove(dpidStr);
+			switchCallbacks.remove(dpidStr);
+		}
+	}
+
+	@Override
+	public boolean hasControl(long dpid) {
+		if (!moduleEnabled) return false;
+		
+		LeaderLatch latch = switchLatches.get(HexString.toHexString(dpid));
+		
+		if (latch == null) {
+			log.warn("No leader latch for dpid {}", HexString.toHexString(dpid));
+			return false;
+		}
+		
+		try {
+			return latch.getLeader().getId().equals(mastershipId);
+		} catch (Exception e) {
+			//TODO swallow exception?
+			return false;
+		}
+	}
+
+	@Override
+	public void setMastershipId(String id) {
+		mastershipId = id;
+	}
+
+	@Override
+	public String getMastershipId() {
+		return mastershipId;
+	}
+	
+	@Override
+	public Collection<String> getAllControllers() throws RegistryException {
+		if (!moduleEnabled) return null;
+		
+		log.debug("Getting all controllers");
+		
+		List<String> controllers = new ArrayList<String>();
+		for (ChildData data : controllerCache.getCurrentData()){
+
+			String d = null;
+			try {
+				d = new String(data.getData(), "UTF-8");
+			} catch (UnsupportedEncodingException e) {
+				throw new RegistryException("Error encoding string", e);
+			}
+
+			controllers.add(d);
+		}
+		return controllers;
+	}
+
+	@Override
+	public void registerController(String id) throws RegistryException {
+		if (!moduleEnabled) return;
+		
+		byte bytes[] = null;
+		try {
+			bytes = id.getBytes("UTF-8");
+		} catch (UnsupportedEncodingException e1) {
+			throw new RegistryException("Error encoding string", e1);
+		}
+		
+		String path = controllerPath + "/" + id;
+		
+		log.info("Registering controller with id {}", id);
+		
+		//Create ephemeral node in controller registry
+		try {
+			client.create().withProtection().withMode(CreateMode.EPHEMERAL)
+					.forPath(path, bytes);
+		} catch (Exception e) {
+			throw new RegistryException("Error contacting the Zookeeper service", e);
+		}
+	}
+	
+	@Override
+	public String getControllerForSwitch(long dpid) throws RegistryException {
+		if (!moduleEnabled) return null;
+		// TODO Work out how we should store this controller/switch data.
+		// The leader latch might be a index to the /controllers collections
+		// which holds more info on the controller (how to talk to it for example).
+		
+		
+		String strDpid = HexString.toHexString(dpid);
+		LeaderLatch latch = switchLatches.get(strDpid);
+		
+		if (latch == null){
+			log.warn("Tried to get controller for non-existent switch");
+			return null;
+		}
+		
+		Participant leader = null;
+		try {
+			leader = latch.getLeader();
+		} catch (Exception e) {
+			throw new RegistryException("Error contacting the Zookeeper service", e);
+		}
+		
+		return leader.getId();
+	}
+	
+	@Override
+	public Collection<Long> getSwitchesControlledByController(String controllerId) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	
+
+	@Override
+	public Collection<Map<String, String>> getAllSwitches() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	
+	/*
+	 * IFloodlightModule
+	 */
+	
+	@Override
+	public Collection<Class<? extends IFloodlightService>> getModuleServices() {
+		Collection<Class<? extends IFloodlightService>> l = 
+				new ArrayList<Class<? extends IFloodlightService>>();
+		l.add(IControllerRegistryService.class);
+		return l;
+	}
+	
+	@Override
+	public Map<Class<? extends IFloodlightService>, IFloodlightService> getServiceImpls() {
+		Map<Class<? extends IFloodlightService>, IFloodlightService> m = 
+				new HashMap<Class<? extends IFloodlightService>, IFloodlightService>();
+		m.put(IControllerRegistryService.class,  this);
+		return m;
+	}
+	
+	@Override
+	public Collection<Class<? extends IFloodlightService>> getModuleDependencies() {
+		// no module dependencies
+		return null;
+	}
+	
+	@Override
+	public void init (FloodlightModuleContext context) throws FloodlightModuleException {
+		
+		//Read config to see if we should try and connect to zookeeper
+		Map<String, String> configOptions = context.getConfigParams(this);
+		String enableZookeeper = configOptions.get("enableZookeeper");
+		if (enableZookeeper != null) {
+			log.info("Enabling Mastership module - requires Zookeeper connection");
+			moduleEnabled = true;
+		}
+		else {
+			log.info("Mastership module is disabled");
+			return;
+		}
+		
+		try {
+			String localHostname = java.net.InetAddress.getLocalHost().getHostName();
+			mastershipId = localHostname;
+			log.debug("Setting mastership id to {}", mastershipId);
+		} catch (UnknownHostException e) {
+			// TODO Handle this exception
+			e.printStackTrace();
+		}
+
+		switchLatches = new HashMap<String, LeaderLatch>();
+		switchCallbacks = new HashMap<String, ControlChangeCallback>();
+		
+		//RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
+		RetryPolicy retryPolicy = new RetryOneTime(0);
+		client = CuratorFrameworkFactory.newClient(connectionString, retryPolicy);
+		
+		client.start();
+		
+		client = client.usingNamespace(namespace);
+		
+		controllerCache = new PathChildrenCache(client, controllerPath, true);
+		
+		try {
+			controllerCache.start(StartMode.BUILD_INITIAL_CACHE);
+		} catch (Exception e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+	
+	@Override
+	public void startUp (FloodlightModuleContext context) {
+		// Nothing to be done on startup
+	}
+
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/RegistryRouteResource.java b/src/main/java/net/onrc/onos/registry/controller/RegistryRouteResource.java
new file mode 100644
index 0000000..5dadafa
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/RegistryRouteResource.java
@@ -0,0 +1,32 @@
+package net.onrc.onos.registry.controller;
+
+import org.restlet.resource.ServerResource;
+import org.restlet.resource.Get;
+import org.restlet.resource.Post;
+import org.restlet.resource.Delete;
+
+import org.slf4j.LoggerFactory;
+import org.slf4j.Logger;
+
+public class RegistryRouteResource extends ServerResource {
+
+	protected static Logger log = LoggerFactory.getLogger(RegistryRouteResource.class);
+
+	@Get
+	public String get(String fmJson) {
+		// TODO
+		return null;
+	}
+	
+	@Post
+	public String store (String fmJson) {
+		//TODO
+		return null;
+	}
+	
+	@Delete
+	public String delete (String fmJson) {
+		//TODO
+		return null;
+	}
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/RegistryRunner.java b/src/main/java/net/onrc/onos/registry/controller/RegistryRunner.java
new file mode 100644
index 0000000..8522893
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/RegistryRunner.java
@@ -0,0 +1,72 @@
+package net.onrc.onos.registry.controller;
+
+import net.floodlightcontroller.core.module.FloodlightModuleContext;
+import net.floodlightcontroller.core.module.FloodlightModuleException;
+import net.onrc.onos.registry.controller.IControllerRegistryService.ControlChangeCallback;
+
+import org.openflow.util.HexString;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Used for lightweight testing of the mastership module without having
+ * to load up the entire ONOS.
+ * @author jono
+ *
+ */
+public class RegistryRunner {
+	protected static Logger log = LoggerFactory.getLogger(RegistryRunner.class);
+
+	public static void main(String args[]){
+		FloodlightModuleContext fmc = new FloodlightModuleContext();
+		RegistryManager rm = new RegistryManager();
+		
+		fmc.addConfigParam(rm, "enableZookeeper", "true");
+		
+		String id = null;
+		if (args.length > 0){
+			id = args[0];
+			log.info("Using unique id: {}", id);
+		}
+		
+		try {
+			rm.init(fmc);
+			rm.startUp(fmc);
+			
+			if (id != null){
+				rm.setMastershipId(id);
+			}
+				
+			rm.requestControl(1L, 
+				new ControlChangeCallback(){
+					@Override
+					public void controlChanged(long dpid, boolean isMaster) {
+						if (isMaster){
+							log.debug("Callback for becoming master for {}", HexString.toHexString(dpid));
+						}
+						else {
+							log.debug("Callback for losing mastership for {}", HexString.toHexString(dpid));
+						}
+					}
+				});
+			
+			rm.registerController(id);
+			
+			Thread.sleep(5000);
+			
+			//"Server" loop
+			while (true) {
+				Thread.sleep(60000);
+			}
+			
+		} catch (FloodlightModuleException e) {
+			e.printStackTrace();
+		} catch (InterruptedException e) {
+			e.printStackTrace();
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+		
+		log.debug("is master: {}", rm.hasControl(1L));
+	}
+}
diff --git a/src/main/java/net/onrc/onos/registry/controller/RegistryWebRoutable.java b/src/main/java/net/onrc/onos/registry/controller/RegistryWebRoutable.java
new file mode 100644
index 0000000..8b5123b
--- /dev/null
+++ b/src/main/java/net/onrc/onos/registry/controller/RegistryWebRoutable.java
@@ -0,0 +1,23 @@
+package net.onrc.onos.registry.controller;
+
+import org.restlet.Context;
+import org.restlet.Restlet;
+import org.restlet.routing.Router;
+
+import net.floodlightcontroller.restserver.RestletRoutable;
+
+public class RegistryWebRoutable implements RestletRoutable {
+
+	@Override
+	public Restlet getRestlet(Context context) {
+		Router router = new Router(context);
+		router.attach("/json", RegistryRouteResource.class);
+		return router;
+	}
+
+	@Override
+	public String basePath() {
+		return "/wm/registry";
+	}
+
+}