diff --git a/core/language/en-GB/Fields.multids b/core/language/en-GB/Fields.multids
index 6b4823c02f9..d1eeabd4295 100644
--- a/core/language/en-GB/Fields.multids
+++ b/core/language/en-GB/Fields.multids
@@ -35,3 +35,4 @@ title: The unique name of a tiddler
 toc-link: Suppresses the tiddler's link in a Table of Contents tree if set to: ''no'' 
 type: The content type of a tiddler
 version: Version information for a plugin
+_is_skinny: If present, indicates that the tiddler text field must be loaded from the server
diff --git a/core/language/en-GB/Misc.multids b/core/language/en-GB/Misc.multids
index ee1d0320ef5..861bb68995c 100644
--- a/core/language/en-GB/Misc.multids
+++ b/core/language/en-GB/Misc.multids
@@ -28,6 +28,7 @@ Error/Filter: Filter error
 Error/FilterSyntax: Syntax error in filter expression
 Error/IsFilterOperator: Filter Error: Unknown operand for the 'is' filter operator
 Error/LoadingPluginLibrary: Error loading plugin library
+Error/NetworkErrorAlert: `<h2>''Network Error''</h2>It looks like the connection to the server has been lost. This may indicate a problem with your network connection. Please attempt to restore network connectivity before continuing.<br><br>''Any unsaved changes will be automatically synchronised when connectivity is restored''.`
 Error/RecursiveTransclusion: Recursive transclusion error in transclude widget
 Error/RetrievingSkinny: Error retrieving skinny tiddler list
 Error/SavingToTWEdit: Error saving to TWEdit
diff --git a/core/modules/server/routes/get-file.js b/core/modules/server/routes/get-file.js
index 3429c4cd208..2a0ef647abf 100644
--- a/core/modules/server/routes/get-file.js
+++ b/core/modules/server/routes/get-file.js
@@ -19,22 +19,16 @@ exports.path = /^\/files\/(.+)$/;
 exports.handler = function(request,response,state) {
 	var path = require("path"),
 		fs = require("fs"),
-		util = require("util");
-	var filename = path.resolve($tw.boot.wikiPath,"files",decodeURIComponent(state.params[0])),
+		util = require("util"),
+		suppliedFilename = decodeURIComponent(state.params[0]),
+		filename = path.resolve($tw.boot.wikiPath,"files",suppliedFilename),
 		extension = path.extname(filename);
 	fs.readFile(filename,function(err,content) {
 		var status,content,type = "text/plain";
 		if(err) {
-			if(err.code === "ENOENT") {
-				status = 404;
-				content = "File '" + filename + "' not found";
-			} else if(err.code === "EACCES") {
-				status = 403;
-				content = "You do not have permission to access the file '" + filename + "'";
-			} else {
-				status = 500;
-				content = err.toString();
-			}
+			console.log("Error accessing file " + filename + ": " + err.toString());
+			status = 404;
+			content = "File '" + suppliedFilename + "' not found";
 		} else {
 			status = 200;
 			content = content;
diff --git a/core/modules/server/routes/get-tiddlers-json.js b/core/modules/server/routes/get-tiddlers-json.js
index 3ece35ce13b..8e93733e48d 100644
--- a/core/modules/server/routes/get-tiddlers-json.js
+++ b/core/modules/server/routes/get-tiddlers-json.js
@@ -3,7 +3,7 @@ title: $:/core/modules/server/routes/get-tiddlers-json.js
 type: application/javascript
 module-type: route
 
-GET /recipes/default/tiddlers/tiddlers.json
+GET /recipes/default/tiddlers/tiddlers.json?filter=<filter>
 
 \*/
 (function() {
@@ -12,23 +12,34 @@ GET /recipes/default/tiddlers/tiddlers.json
 /*global $tw: false */
 "use strict";
 
+var DEFAULT_FILTER = "[all[tiddlers]!is[system]sort[title]]";
+
 exports.method = "GET";
 
 exports.path = /^\/recipes\/default\/tiddlers.json$/;
 
 exports.handler = function(request,response,state) {
+	var filter = state.queryParameters.filter || DEFAULT_FILTER;
+	if($tw.wiki.getTiddlerText("$:/config/Server/AllowAllExternalFilters") !== "yes") {
+		if($tw.wiki.getTiddlerText("$:/config/Server/ExternalFilters/" + filter) !== "yes") {
+			console.log("Blocked attempt to GET /recipes/default/tiddlers/tiddlers.json with filter: " + filter);
+			response.writeHead(403);
+			response.end();
+			return;
+		}
+	}
+	var excludeFields = (state.queryParameters.exclude || "text").split(","),
+		titles = state.wiki.filterTiddlers(filter);
 	response.writeHead(200, {"Content-Type": "application/json"});
 	var tiddlers = [];
-	state.wiki.forEachTiddler({sortField: "title"},function(title,tiddler) {
-		var tiddlerFields = {};
-		$tw.utils.each(tiddler.fields,function(field,name) {
-			if(name !== "text") {
-				tiddlerFields[name] = tiddler.getFieldString(name);
-			}
-		});
-		tiddlerFields.revision = state.wiki.getChangeCount(title);
-		tiddlerFields.type = tiddlerFields.type || "text/vnd.tiddlywiki";
-		tiddlers.push(tiddlerFields);
+	$tw.utils.each(titles,function(title) {
+		var tiddler = state.wiki.getTiddler(title);
+		if(tiddler) {
+			var tiddlerFields = tiddler.getFieldStrings({exclude: excludeFields});
+			tiddlerFields.revision = state.wiki.getChangeCount(title);
+			tiddlerFields.type = tiddlerFields.type || "text/vnd.tiddlywiki";
+			tiddlers.push(tiddlerFields);
+		}
 	});
 	var text = JSON.stringify(tiddlers);
 	response.end(text,"utf8");
diff --git a/core/modules/server/server.js b/core/modules/server/server.js
index 3225b95f39d..3226cacd727 100644
--- a/core/modules/server/server.js
+++ b/core/modules/server/server.js
@@ -16,7 +16,8 @@ if($tw.node) {
 	var util = require("util"),
 		fs = require("fs"),
 		url = require("url"),
-		path = require("path");
+		path = require("path"),
+		querystring = require("querystring");
 }
 
 /*
@@ -162,6 +163,7 @@ Server.prototype.requestHandler = function(request,response) {
 	state.wiki = self.wiki;
 	state.server = self;
 	state.urlInfo = url.parse(request.url);
+	state.queryParameters = querystring.parse(state.urlInfo.query);
 	// Get the principals authorized to access this resource
 	var authorizationType = this.methodMappings[request.method] || "readers";
 	// Check for the CSRF header if this is a write
@@ -236,6 +238,7 @@ host: optional host address (falls back to value of "host" variable)
 prefix: optional prefix (falls back to value of "path-prefix" variable)
 */
 Server.prototype.listen = function(port,host,prefix) {
+	var self = this;
 	// Handle defaults for port and host
 	port = port || this.get("port");
 	host = host || this.get("host");
@@ -244,19 +247,24 @@ Server.prototype.listen = function(port,host,prefix) {
 	if(parseInt(port,10).toString() !== port) {
 		port = process.env[port] || 8080;
 	}
-	$tw.utils.log("Serving on " + this.protocol + "://" + host + ":" + port + prefix,"brown/orange");
-	$tw.utils.log("(press ctrl-C to exit)","red");
 	// Warn if required plugins are missing
 	if(!$tw.wiki.getTiddler("$:/plugins/tiddlywiki/tiddlyweb") || !$tw.wiki.getTiddler("$:/plugins/tiddlywiki/filesystem")) {
 		$tw.utils.warning("Warning: Plugins required for client-server operation (\"tiddlywiki/filesystem\" and \"tiddlywiki/tiddlyweb\") are missing from tiddlywiki.info file");
 	}
-	// Listen
+	// Create the server
 	var server;
 	if(this.listenOptions) {
 		server = this.transport.createServer(this.listenOptions,this.requestHandler.bind(this));
 	} else {
 		server = this.transport.createServer(this.requestHandler.bind(this));
 	}
+	// Display the port number after we've started listening (the port number might have been specified as zero, in which case we will get an assigned port)
+	server.on("listening",function() {
+		var address = server.address();
+		$tw.utils.log("Serving on " + self.protocol + "://" + address.address + ":" + address.port + prefix,"brown/orange");
+		$tw.utils.log("(press ctrl-C to exit)","red");
+	});
+	// Listen
 	return server.listen(port,host);
 };
 
diff --git a/core/modules/startup/startup.js b/core/modules/startup/startup.js
index 4cd53dfcded..ad1416bf39c 100755
--- a/core/modules/startup/startup.js
+++ b/core/modules/startup/startup.js
@@ -128,7 +128,7 @@ exports.startup = function() {
 	// Set up the syncer object if we've got a syncadaptor
 	if($tw.syncadaptor) {
 		$tw.syncer = new $tw.Syncer({wiki: $tw.wiki, syncadaptor: $tw.syncadaptor});
-	} 
+	}
 	// Setup the saver handler
 	$tw.saverHandler = new $tw.SaverHandler({
 		wiki: $tw.wiki,
diff --git a/core/modules/syncer.js b/core/modules/syncer.js
index 0b84be750ea..f39646eace7 100644
--- a/core/modules/syncer.js
+++ b/core/modules/syncer.js
@@ -3,7 +3,7 @@ title: $:/core/modules/syncer.js
 type: application/javascript
 module-type: global
 
-The syncer tracks changes to the store. If a syncadaptor is used then individual tiddlers are synchronised through it. If there is no syncadaptor then the entire wiki is saved via saver modules.
+The syncer tracks changes to the store and synchronises them to a remote data store represented as a "sync adaptor"
 
 \*/
 (function(){
@@ -23,8 +23,10 @@ Syncer.prototype.titleSyncFilter = "$:/config/SyncFilter";
 Syncer.prototype.titleSyncPollingInterval = "$:/config/SyncPollingInterval";
 Syncer.prototype.titleSyncDisableLazyLoading = "$:/config/SyncDisableLazyLoading";
 Syncer.prototype.titleSavedNotification = "$:/language/Notifications/Save/Done";
+Syncer.prototype.titleSyncThrottleInterval = "$:/config/SyncThrottleInterval";
 Syncer.prototype.taskTimerInterval = 1 * 1000; // Interval for sync timer
 Syncer.prototype.throttleInterval = 1 * 1000; // Defer saving tiddlers if they've changed in the last 1s...
+Syncer.prototype.errorRetryInterval = 5 * 1000; // Interval to retry after an error
 Syncer.prototype.fallbackInterval = 10 * 1000; // Unless the task is older than 10s
 Syncer.prototype.pollTimerInterval = 60 * 1000; // Interval for polling for changes from the adaptor
 
@@ -36,6 +38,7 @@ wiki: wiki to be synced
 function Syncer(options) {
 	var self = this;
 	this.wiki = options.wiki;
+	// Save parameters
 	this.syncadaptor = options.syncadaptor;
 	this.disableUI = !!options.disableUI;
 	this.titleIsLoggedIn = options.titleIsLoggedIn || this.titleIsLoggedIn;
@@ -43,27 +46,54 @@ function Syncer(options) {
 	this.titleSyncFilter = options.titleSyncFilter || this.titleSyncFilter;
 	this.titleSavedNotification = options.titleSavedNotification || this.titleSavedNotification;
 	this.taskTimerInterval = options.taskTimerInterval || this.taskTimerInterval;
-	this.throttleInterval = options.throttleInterval || this.throttleInterval;
+	this.throttleInterval = options.throttleInterval || parseInt(this.wiki.getTiddlerText(this.titleSyncThrottleInterval,""),10) || this.throttleInterval;
+	this.errorRetryInterval = options.errorRetryInterval || this.errorRetryInterval;
 	this.fallbackInterval = options.fallbackInterval || this.fallbackInterval;
 	this.pollTimerInterval = options.pollTimerInterval || parseInt(this.wiki.getTiddlerText(this.titleSyncPollingInterval,""),10) || this.pollTimerInterval;
 	this.logging = "logging" in options ? options.logging : true;
 	// Make a logger
 	this.logger = new $tw.utils.Logger("syncer" + ($tw.browser ? "-browser" : "") + ($tw.node ? "-server" : "")  + (this.syncadaptor.name ? ("-" + this.syncadaptor.name) : ""),{
-			colour: "cyan",
-			enable: this.logging
-		});
+		colour: "cyan",
+		enable: this.logging,
+		saveHistory: true
+	});
+	if(this.syncadaptor.setLoggerSaveBuffer) {
+		this.syncadaptor.setLoggerSaveBuffer(this.logger);
+	}
 	// Compile the dirty tiddler filter
 	this.filterFn = this.wiki.compileFilter(this.wiki.getTiddlerText(this.titleSyncFilter));
 	// Record information for known tiddlers
 	this.readTiddlerInfo();
-	// Tasks are {type: "load"/"save"/"delete", title:, queueTime:, lastModificationTime:}
-	this.taskQueue = {}; // Hashmap of tasks yet to be performed
-	this.taskInProgress = {}; // Hash of tasks in progress
+	this.titlesToBeLoaded = {}; // Hashmap of titles of tiddlers that need loading from the server
+	this.titlesHaveBeenLazyLoaded = {}; // Hashmap of titles of tiddlers that have already been lazily loaded from the server
+	// Timers
 	this.taskTimerId = null; // Timer for task dispatch
 	this.pollTimerId = null; // Timer for polling server
+	// Number of outstanding requests
+	this.numTasksInProgress = 0;
 	// Listen out for changes to tiddlers
 	this.wiki.addEventListener("change",function(changes) {
-		self.syncToServer(changes);
+		// Filter the changes to just include ones that are being synced
+		var filteredChanges = self.getSyncedTiddlers(function(callback) {
+			$tw.utils.each(changes,function(change,title) {
+				var tiddler = self.wiki.tiddlerExists(title) && self.wiki.getTiddler(title);
+				callback(tiddler,title);
+			});
+		});
+		if(filteredChanges.length > 0) {
+			self.processTaskQueue();
+		} else {
+			// Look for deletions of tiddlers we're already syncing	
+			var outstandingDeletion = false
+			$tw.utils.each(changes,function(change,title,object) {
+				if(change.deleted && $tw.utils.hop(self.tiddlerInfo,title)) {
+					outstandingDeletion = true;
+				}
+			});
+			if(outstandingDeletion) {
+				self.processTaskQueue();
+			}
+		}
 	});
 	// Browser event handlers
 	if($tw.browser && !this.disableUI) {
@@ -86,6 +116,9 @@ function Syncer(options) {
 		$tw.rootWidget.addEventListener("tm-server-refresh",function() {
 			self.handleRefreshEvent();
 		});
+		$tw.rootWidget.addEventListener("tm-copy-syncer-logs-to-clipboard",function() {
+			$tw.utils.copyToClipboard($tw.utils.getSystemInfo() + "\n\nLog:\n" + self.logger.getBuffer());
+		});
 	}
 	// Listen out for lazyLoad events
 	if(!this.disableUI && $tw.wiki.getTiddlerText(this.titleSyncDisableLazyLoading) !== "yes") {
@@ -100,45 +133,83 @@ function Syncer(options) {
 	});
 }
 
+/*
+Show a generic network error alert
+*/
+Syncer.prototype.showErrorAlert = function() {
+console.log($tw.language.getString("Error/NetworkErrorAlert"))
+	this.logger.alert($tw.language.getString("Error/NetworkErrorAlert"));
+};
+
+/*
+Return an array of the tiddler titles that are subjected to syncing
+*/
+Syncer.prototype.getSyncedTiddlers = function(source) {
+	return this.filterFn.call(this.wiki,source);
+};
+
+/*
+Return an array of the tiddler titles that are subjected to syncing
+*/
+Syncer.prototype.getTiddlerRevision = function(title) {
+	if(this.syncadaptor && this.syncadaptor.getTiddlerRevision) {
+		return this.syncadaptor.getTiddlerRevision(title);
+	} else {
+		return this.wiki.getTiddler(title).fields.revision;	
+	} 
+};
+
 /*
 Read (or re-read) the latest tiddler info from the store
 */
 Syncer.prototype.readTiddlerInfo = function() {
 	// Hashmap by title of {revision:,changeCount:,adaptorInfo:}
+	// "revision" is the revision of the tiddler last seen on the server, and "changecount" is the corresponding local changecount
 	this.tiddlerInfo = {};
 	// Record information for known tiddlers
 	var self = this,
-		tiddlers = this.filterFn.call(this.wiki);
+		tiddlers = this.getSyncedTiddlers();
 	$tw.utils.each(tiddlers,function(title) {
-		var tiddler = self.wiki.getTiddler(title);
+		var tiddler = self.wiki.tiddlerExists(title) && self.wiki.getTiddler(title);
 		self.tiddlerInfo[title] = {
-			revision: tiddler.fields.revision,
+			revision: self.getTiddlerRevision(title),
 			adaptorInfo: self.syncadaptor && self.syncadaptor.getTiddlerInfo(tiddler),
-			changeCount: self.wiki.getChangeCount(title),
-			hasBeenLazyLoaded: false
+			changeCount: self.wiki.getChangeCount(title)
 		};
 	});
 };
 
-/*
-Create an tiddlerInfo structure if it doesn't already exist
-*/
-Syncer.prototype.createTiddlerInfo = function(title) {
-	if(!$tw.utils.hop(this.tiddlerInfo,title)) {
-		this.tiddlerInfo[title] = {
-			revision: null,
-			adaptorInfo: {},
-			changeCount: -1,
-			hasBeenLazyLoaded: false
-		};
-	}
-};
-
 /*
 Checks whether the wiki is dirty (ie the window shouldn't be closed)
 */
 Syncer.prototype.isDirty = function() {
-	return (this.numTasksInQueue() > 0) || (this.numTasksInProgress() > 0);
+	this.logger.log("Checking dirty status");
+	// Check tiddlers that are in the store and included in the filter function
+	var titles = this.getSyncedTiddlers();
+	for(var index=0; index<titles.length; index++) {
+		var title = titles[index],
+			tiddlerInfo = this.tiddlerInfo[title];
+		if(this.wiki.tiddlerExists(title)) {
+			if(tiddlerInfo) {
+				// If the tiddler is known on the server and has been modified locally then it needs to be saved to the server
+				if($tw.wiki.getChangeCount(title) > tiddlerInfo.changeCount) {
+					return true;
+				}
+			} else {
+				// If the tiddler isn't known on the server then it needs to be saved to the server
+				return true;
+			}
+		}
+	}
+	// Check tiddlers that are known from the server but not currently in the store
+	titles = Object.keys(this.tiddlerInfo);
+	for(index=0; index<titles.length; index++) {
+		if(!this.wiki.tiddlerExists(titles[index])) {
+			// There must be a pending delete
+			return true;
+		}
+	}
+	return false;
 };
 
 /*
@@ -146,23 +217,26 @@ Update the document body with the class "tc-dirty" if the wiki has unsaved/unsyn
 */
 Syncer.prototype.updateDirtyStatus = function() {
 	if($tw.browser && !this.disableUI) {
-		$tw.utils.toggleClass(document.body,"tc-dirty",this.isDirty());
+		var dirty = this.isDirty();
+		$tw.utils.toggleClass(document.body,"tc-dirty",dirty);
+		if(!dirty) {
+			this.logger.clearAlerts();
+		}
 	}
 };
 
 /*
 Save an incoming tiddler in the store, and updates the associated tiddlerInfo
 */
-Syncer.prototype.storeTiddler = function(tiddlerFields,hasBeenLazyLoaded) {
+Syncer.prototype.storeTiddler = function(tiddlerFields) {
 	// Save the tiddler
 	var tiddler = new $tw.Tiddler(tiddlerFields);
 	this.wiki.addTiddler(tiddler);
 	// Save the tiddler revision and changeCount details
 	this.tiddlerInfo[tiddlerFields.title] = {
-		revision: tiddlerFields.revision,
+		revision: this.getTiddlerRevision(tiddlerFields.title),
 		adaptorInfo: this.syncadaptor.getTiddlerInfo(tiddler),
-		changeCount: this.wiki.getChangeCount(tiddlerFields.title),
-		hasBeenLazyLoaded: hasBeenLazyLoaded !== undefined ? hasBeenLazyLoaded : true
+		changeCount: this.wiki.getChangeCount(tiddlerFields.title)
 	};
 };
 
@@ -176,14 +250,14 @@ Syncer.prototype.getStatus = function(callback) {
 		this.syncadaptor.getStatus(function(err,isLoggedIn,username,isReadOnly,isAnonymous) {
 			if(err) {
 				self.logger.alert(err);
-				return;
-			}
-			// Set the various status tiddlers
-			self.wiki.addTiddler({title: self.titleIsReadOnly,text: isReadOnly ? "yes" : "no"});
-			self.wiki.addTiddler({title: self.titleIsAnonymous,text: isAnonymous ? "yes" : "no"});
-			self.wiki.addTiddler({title: self.titleIsLoggedIn,text: isLoggedIn ? "yes" : "no"});
-			if(isLoggedIn) {
-				self.wiki.addTiddler({title: self.titleUserName,text: username || ""});
+			} else {
+				// Set the various status tiddlers
+				self.wiki.addTiddler({title: self.titleIsReadOnly,text: isReadOnly ? "yes" : "no"});
+				self.wiki.addTiddler({title: self.titleIsAnonymous,text: isAnonymous ? "yes" : "no"});
+				self.wiki.addTiddler({title: self.titleIsLoggedIn,text: isLoggedIn ? "yes" : "no"});
+				if(isLoggedIn) {
+					self.wiki.addTiddler({title: self.titleUserName,text: username || ""});
+				}
 			}
 			// Invoke the callback
 			if(callback) {
@@ -199,91 +273,112 @@ Syncer.prototype.getStatus = function(callback) {
 Synchronise from the server by reading the skinny tiddler list and queuing up loads for any tiddlers that we don't already have up to date
 */
 Syncer.prototype.syncFromServer = function() {
-	if(this.syncadaptor && this.syncadaptor.getSkinnyTiddlers) {
-		this.logger.log("Retrieving skinny tiddler list");
-		var self = this;
-		if(this.pollTimerId) {
-			clearTimeout(this.pollTimerId);
-			this.pollTimerId = null;
-		}
-		this.syncadaptor.getSkinnyTiddlers(function(err,tiddlers) {
-			// Trigger the next sync
+	var self = this,
+		cancelNextSync = function() {
+			if(self.pollTimerId) {
+				clearTimeout(self.pollTimerId);
+				self.pollTimerId = null;
+			}
+		},
+		triggerNextSync = function() {
 			self.pollTimerId = setTimeout(function() {
 				self.pollTimerId = null;
 				self.syncFromServer.call(self);
 			},self.pollTimerInterval);
+		};
+	if(this.syncadaptor && this.syncadaptor.getUpdatedTiddlers) {
+		this.logger.log("Retrieving updated tiddler list");
+		cancelNextSync();
+		this.syncadaptor.getUpdatedTiddlers(self,function(err,updates) {
+			triggerNextSync();
+			if(err) {
+				self.showErrorAlert();
+				self.logger.log($tw.language.getString("Error/RetrievingSkinny") + ":",err);
+				return;
+			}
+			if(updates) {
+				$tw.utils.each(updates.modifications,function(title) {
+					self.titlesToBeLoaded[title] = true;
+				});
+				$tw.utils.each(updates.deletions,function(title) {
+					delete self.tiddlerInfo[title];
+					self.logger.log("Deleting tiddler missing from server:",title);
+					self.wiki.deleteTiddler(title);
+				});
+				if(updates.modifications.length > 0 || updates.deletions.length > 0) {
+					self.processTaskQueue();
+				}				
+			}
+		});
+	} else if(this.syncadaptor && this.syncadaptor.getSkinnyTiddlers) {
+		this.logger.log("Retrieving skinny tiddler list");
+		cancelNextSync();
+		this.syncadaptor.getSkinnyTiddlers(function(err,tiddlers) {
+			triggerNextSync();
 			// Check for errors
 			if(err) {
-				self.logger.alert($tw.language.getString("Error/RetrievingSkinny") + ":",err);
+				self.showErrorAlert();
+				self.logger.log($tw.language.getString("Error/RetrievingSkinny") + ":",err);
 				return;
 			}
+			// Keep track of which tiddlers we already know about have been reported this time
+			var previousTitles = Object.keys(self.tiddlerInfo);
 			// Process each incoming tiddler
 			for(var t=0; t<tiddlers.length; t++) {
 				// Get the incoming tiddler fields, and the existing tiddler
 				var tiddlerFields = tiddlers[t],
 					incomingRevision = tiddlerFields.revision + "",
-					tiddler = self.wiki.getTiddler(tiddlerFields.title),
+					tiddler = self.wiki.tiddlerExists(tiddlerFields.title) && self.wiki.getTiddler(tiddlerFields.title),
 					tiddlerInfo = self.tiddlerInfo[tiddlerFields.title],
-					currRevision = tiddlerInfo ? tiddlerInfo.revision : null;
+					currRevision = tiddlerInfo ? tiddlerInfo.revision : null,
+					indexInPreviousTitles = previousTitles.indexOf(tiddlerFields.title);
+				if(indexInPreviousTitles !== -1) {
+					previousTitles.splice(indexInPreviousTitles,1);
+				}
 				// Ignore the incoming tiddler if it's the same as the revision we've already got
 				if(currRevision !== incomingRevision) {
-					// Do a full load if we've already got a fat version of the tiddler
-					if(tiddler && tiddler.fields.text !== undefined) {
-						// Do a full load of this tiddler
-						self.enqueueSyncTask({
-							type: "load",
-							title: tiddlerFields.title
-						});
-					} else {
-						// Load the skinny version of the tiddler
-						self.storeTiddler(tiddlerFields,false);
+					// Only load the skinny version if we don't already have a fat version of the tiddler
+					if(!tiddler || tiddler.fields.text === undefined) {
+						self.storeTiddler(tiddlerFields);
 					}
+					// Do a full load of this tiddler
+					self.titlesToBeLoaded[tiddlerFields.title] = true;
 				}
 			}
+			// Delete any tiddlers that were previously reported but missing this time
+			$tw.utils.each(previousTitles,function(title) {
+				delete self.tiddlerInfo[title];
+				self.logger.log("Deleting tiddler missing from server:",title);
+				self.wiki.deleteTiddler(title);
+			});
+			self.processTaskQueue();
 		});
 	}
 };
 
 /*
-Synchronise a set of changes to the server
+Force load a tiddler from the server
 */
-Syncer.prototype.syncToServer = function(changes) {
-	var self = this,
-		now = Date.now(),
-		filteredChanges = this.filterFn.call(this.wiki,function(callback) {
-			$tw.utils.each(changes,function(change,title) {
-				var tiddler = self.wiki.getTiddler(title);
-				callback(tiddler,title);
-			});
-		});
-	$tw.utils.each(changes,function(change,title,object) {
-		// Process the change if it is a deletion of a tiddler we're already syncing, or is on the filtered change list
-		if((change.deleted && $tw.utils.hop(self.tiddlerInfo,title)) || filteredChanges.indexOf(title) !== -1) {
-			// Queue a task to sync this tiddler
-			self.enqueueSyncTask({
-				type: change.deleted ? "delete" : "save",
-				title: title
-			});
-		}
-	});
+Syncer.prototype.enqueueLoadTiddler = function(title) {
+	this.titlesToBeLoaded[title] = true;
+	this.processTaskQueue();
 };
 
 /*
 Lazily load a skinny tiddler if we can
 */
 Syncer.prototype.handleLazyLoadEvent = function(title) {
+	// Ignore if the syncadaptor doesn't handle it
+	if(!this.syncadaptor.supportsLazyLoading) {
+		return;
+	}
 	// Don't lazy load the same tiddler twice
-	var info = this.tiddlerInfo[title];
-	if(!info || !info.hasBeenLazyLoaded) {
+	if(!this.titlesHaveBeenLazyLoaded[title]) {
 		// Don't lazy load if the tiddler isn't included in the sync filter
-		if(this.filterFn.call(this.wiki).indexOf(title) !== -1) {
-			this.createTiddlerInfo(title);
-			this.tiddlerInfo[title].hasBeenLazyLoaded = true;
-			// Queue up a sync task to load this tiddler
-			this.enqueueSyncTask({
-				type: "load",
-				title: title
-			});
+		if(this.getSyncedTiddlers().indexOf(title) !== -1) {
+			// Mark the tiddler as needing loading, and having already been lazily loaded
+			this.titlesToBeLoaded[title] = true;
+			this.titlesHaveBeenLazyLoaded[title] = true;
 		}
 	}
 };
@@ -294,7 +389,7 @@ Dispay a password prompt and allow the user to login
 Syncer.prototype.handleLoginEvent = function() {
 	var self = this;
 	this.getStatus(function(err,isLoggedIn,username) {
-		if(!isLoggedIn) {
+		if(!err && !isLoggedIn) {
 			$tw.passwordPrompt.createPrompt({
 				serviceName: $tw.language.getString("LoginToTiddlySpace"),
 				callback: function(data) {
@@ -324,7 +419,7 @@ Syncer.prototype.login = function(username,password,callback) {
 			}
 			self.getStatus(function(err,isLoggedIn,username) {
 				if(callback) {
-					callback(null,isLoggedIn);
+					callback(err,isLoggedIn);
 				}
 			});
 		});
@@ -358,189 +453,180 @@ Syncer.prototype.handleRefreshEvent = function() {
 };
 
 /*
-Queue up a sync task. If there is already a pending task for the tiddler, just update the last modification time
+Process the next task
 */
-Syncer.prototype.enqueueSyncTask = function(task) {
-	var self = this,
-		now = Date.now();
-	// Set the timestamps on this task
-	task.queueTime = now;
-	task.lastModificationTime = now;
-	// Fill in some tiddlerInfo if the tiddler is one we haven't seen before
-	this.createTiddlerInfo(task.title);
-	// Bail if this is a save and the tiddler is already at the changeCount that the server has
-	if(task.type === "save" && this.wiki.getChangeCount(task.title) <= this.tiddlerInfo[task.title].changeCount) {
-		return;
-	}
-	// Check if this tiddler is already in the queue
-	if($tw.utils.hop(this.taskQueue,task.title)) {
-		// this.logger.log("Re-queueing up sync task with type:",task.type,"title:",task.title);
-		var existingTask = this.taskQueue[task.title];
-		// If so, just update the last modification time
-		existingTask.lastModificationTime = task.lastModificationTime;
-		// If the new task is a save then we upgrade the existing task to a save. Thus a pending load is turned into a save if the tiddler changes locally in the meantime. But a pending save is not modified to become a load
-		if(task.type === "save" || task.type === "delete") {
-			existingTask.type = task.type;
+Syncer.prototype.processTaskQueue = function() {
+	var self = this;
+	// Only process a task if the sync adaptor is fully initialised and we're not already performing
+	// a task. If we are already performing a task then we'll dispatch the next one when it completes
+	if((!this.syncadaptor.isReady || this.syncadaptor.isReady()) && this.numTasksInProgress === 0) {
+		// Choose the next task to perform
+		var task = this.chooseNextTask();
+		// Perform the task if we had one
+		if(typeof task === "object" && task !== null) {
+			this.numTasksInProgress += 1;
+			task.run(function(err) {
+				self.numTasksInProgress -= 1;
+				if(err) {
+					self.showErrorAlert();
+					self.logger.log("Sync error while processing " + task.type + " of '" + task.title + "':\n" + err);
+					self.updateDirtyStatus();
+					self.triggerTimeout(self.errorRetryInterval);
+				} else {
+					self.updateDirtyStatus();
+					// Process the next task
+					self.processTaskQueue.call(self);					
+				}
+			});
+		} else {
+			// No task is ready so update the status
+			this.updateDirtyStatus();
+			// And trigger a timeout if there is a pending task
+			if(task === true) {
+				this.triggerTimeout();				
+			}
 		}
 	} else {
-		// this.logger.log("Queuing up sync task with type:",task.type,"title:",task.title);
-		// If it is not in the queue, insert it
-		this.taskQueue[task.title] = task;
-		this.updateDirtyStatus();
+		this.updateDirtyStatus();		
 	}
-	// Process the queue
-	$tw.utils.nextTick(function() {self.processTaskQueue.call(self);});
 };
 
-/*
-Return the number of tasks in progress
-*/
-Syncer.prototype.numTasksInProgress = function() {
-	return $tw.utils.count(this.taskInProgress);
-};
-
-/*
-Return the number of tasks in the queue
-*/
-Syncer.prototype.numTasksInQueue = function() {
-	return $tw.utils.count(this.taskQueue);
-};
-
-/*
-Trigger a timeout if one isn't already outstanding
-*/
-Syncer.prototype.triggerTimeout = function() {
+Syncer.prototype.triggerTimeout = function(interval) {
 	var self = this;
 	if(!this.taskTimerId) {
 		this.taskTimerId = setTimeout(function() {
 			self.taskTimerId = null;
 			self.processTaskQueue.call(self);
-		},self.taskTimerInterval);
+		},interval || self.taskTimerInterval);
 	}
 };
 
 /*
-Process the task queue, performing the next task if appropriate
+Choose the next sync task. We prioritise saves, then deletes, then loads from the server
+
+Returns either a task object, null if there's no upcoming tasks, or the boolean true if there are pending tasks that aren't yet due
 */
-Syncer.prototype.processTaskQueue = function() {
-	var self = this;
-	// Only process a task if the sync adaptor is fully initialised and we're not already performing a task. If we are already performing a task then we'll dispatch the next one when it completes
-	if((!this.syncadaptor.isReady || this.syncadaptor.isReady()) && this.numTasksInProgress() === 0) {
-		// Choose the next task to perform
-		var task = this.chooseNextTask();
-		// Perform the task if we had one
-		if(task) {
-			// Remove the task from the queue and add it to the in progress list
-			delete this.taskQueue[task.title];
-			this.taskInProgress[task.title] = task;
-			this.updateDirtyStatus();
-			// Dispatch the task
-			this.dispatchTask(task,function(err) {
-				if(err) {
-					self.logger.alert("Sync error while processing '" + task.title + "':\n" + err);
+Syncer.prototype.chooseNextTask = function() {
+	var thresholdLastSaved = (new Date()) - this.throttleInterval,
+		havePending = null;
+	// First we look for tiddlers that have been modified locally and need saving back to the server
+	var titles = this.getSyncedTiddlers();
+	for(var index=0; index<titles.length; index++) {
+		var title = titles[index],
+			tiddler = this.wiki.tiddlerExists(title) && this.wiki.getTiddler(title),
+			tiddlerInfo = this.tiddlerInfo[title];
+		if(tiddler) {
+			// If the tiddler is not known on the server, or has been modified locally no more recently than the threshold then it needs to be saved to the server
+			var hasChanged = !tiddlerInfo || $tw.wiki.getChangeCount(title) > tiddlerInfo.changeCount,
+				isReadyToSave = !tiddlerInfo || !tiddlerInfo.timestampLastSaved || tiddlerInfo.timestampLastSaved < thresholdLastSaved;
+			if(hasChanged) {
+				if(isReadyToSave) {
+					return new SaveTiddlerTask(this,title); 					
+				} else {
+					havePending = true;
 				}
-				// Mark that this task is no longer in progress
-				delete self.taskInProgress[task.title];
-				self.updateDirtyStatus();
-				// Process the next task
-				self.processTaskQueue.call(self);
-			});
-		} else {
-			// Make sure we've set a time if there wasn't a task to perform, but we've still got tasks in the queue
-			if(this.numTasksInQueue() > 0) {
-				this.triggerTimeout();
 			}
 		}
 	}
-};
-
-/*
-Choose the next applicable task
-*/
-Syncer.prototype.chooseNextTask = function() {
-	var self = this,
-		candidateTask = null,
-		now = Date.now();
-	// Select the best candidate task
-	$tw.utils.each(this.taskQueue,function(task,title) {
-		// Exclude the task if there's one of the same name in progress
-		if($tw.utils.hop(self.taskInProgress,title)) {
-			return;
-		}
-		// Exclude the task if it is a save and the tiddler has been modified recently, but not hit the fallback time
-		if(task.type === "save" && (now - task.lastModificationTime) < self.throttleInterval &&
-			(now - task.queueTime) < self.fallbackInterval) {
-			return;
-		}
-		// Exclude the task if it is newer than the current best candidate
-		if(candidateTask && candidateTask.queueTime < task.queueTime) {
-			return;
+	// Second, we check tiddlers that are known from the server but not currently in the store, and so need deleting on the server
+	titles = Object.keys(this.tiddlerInfo);
+	for(index=0; index<titles.length; index++) {
+		title = titles[index];
+		tiddlerInfo = this.tiddlerInfo[title];
+		tiddler = this.wiki.tiddlerExists(title) && this.wiki.getTiddler(title);
+		if(!tiddler) {
+			return new DeleteTiddlerTask(this,title);
 		}
-		// Now this is our best candidate
-		candidateTask = task;
-	});
-	return candidateTask;
+	}
+	// Check for tiddlers that need loading
+	title = Object.keys(this.titlesToBeLoaded)[0];
+	if(title) {
+		delete this.titlesToBeLoaded[title];
+		return new LoadTiddlerTask(this,title);
+	}
+	// No tasks are ready
+	return havePending;
 };
 
-/*
-Dispatch a task and invoke the callback
-*/
-Syncer.prototype.dispatchTask = function(task,callback) {
-	var self = this;
-	if(task.type === "save") {
-		var changeCount = this.wiki.getChangeCount(task.title),
-			tiddler = this.wiki.getTiddler(task.title);
-		this.logger.log("Dispatching 'save' task:",task.title);
-		if(tiddler) {
-			this.syncadaptor.saveTiddler(tiddler,function(err,adaptorInfo,revision) {
-				if(err) {
-					return callback(err);
-				}
-				// Adjust the info stored about this tiddler
-				self.tiddlerInfo[task.title] = {
-					changeCount: changeCount,
-					adaptorInfo: adaptorInfo,
-					revision: revision
-				};
-				// Invoke the callback
-				callback(null);
-			},{
-				tiddlerInfo: self.tiddlerInfo[task.title]
-			});
-		} else {
-			this.logger.log(" Not Dispatching 'save' task:",task.title,"tiddler does not exist");
-			return callback(null);
-		}
-	} else if(task.type === "load") {
-		// Load the tiddler
-		this.logger.log("Dispatching 'load' task:",task.title);
-		this.syncadaptor.loadTiddler(task.title,function(err,tiddlerFields) {
-			if(err) {
-				return callback(err);
-			}
-			// Store the tiddler
-			if(tiddlerFields) {
-				self.storeTiddler(tiddlerFields,true);
-			}
-			// Invoke the callback
-			callback(null);
-		});
-	} else if(task.type === "delete") {
-		// Delete the tiddler
-		this.logger.log("Dispatching 'delete' task:",task.title);
-		this.syncadaptor.deleteTiddler(task.title,function(err) {
+function SaveTiddlerTask(syncer,title) {
+	this.syncer = syncer;
+	this.title = title;
+	this.type = "save";
+}
+
+SaveTiddlerTask.prototype.run = function(callback) {
+	var self = this,
+		changeCount = this.syncer.wiki.getChangeCount(this.title),
+		tiddler = this.syncer.wiki.tiddlerExists(this.title) && this.syncer.wiki.getTiddler(this.title);
+	this.syncer.logger.log("Dispatching 'save' task:",this.title);
+	if(tiddler) {
+		this.syncer.syncadaptor.saveTiddler(tiddler,function(err,adaptorInfo,revision) {
+			// If there's an error, exit without changing any internal state
 			if(err) {
 				return callback(err);
 			}
-			delete self.tiddlerInfo[task.title];
+			// Adjust the info stored about this tiddler
+			self.syncer.tiddlerInfo[self.title] = {
+				changeCount: changeCount,
+				adaptorInfo: adaptorInfo,
+				revision: revision,
+				timestampLastSaved: new Date()
+			};
 			// Invoke the callback
 			callback(null);
-		},{
-			tiddlerInfo: self.tiddlerInfo[task.title]
 		});
+	} else {
+		this.syncer.logger.log(" Not Dispatching 'save' task:",this.title,"tiddler does not exist");
+		$tw.utils.nextTick(callback(null));
 	}
 };
 
+function DeleteTiddlerTask(syncer,title) {
+	this.syncer = syncer;
+	this.title = title;
+	this.type = "delete";
+}
+
+DeleteTiddlerTask.prototype.run = function(callback) {
+	var self = this;
+	this.syncer.logger.log("Dispatching 'delete' task:",this.title);
+	this.syncer.syncadaptor.deleteTiddler(this.title,function(err) {
+		// If there's an error, exit without changing any internal state
+		if(err) {
+			return callback(err);
+		}
+		// Remove the info stored about this tiddler
+		delete self.syncer.tiddlerInfo[self.title];
+		// Invoke the callback
+		callback(null);
+	},{
+		tiddlerInfo: self.syncer.tiddlerInfo[this.title]
+	});
+};
+
+function LoadTiddlerTask(syncer,title) {
+	this.syncer = syncer;
+	this.title = title;
+	this.type = "load";
+}
+
+LoadTiddlerTask.prototype.run = function(callback) {
+	var self = this;
+	this.syncer.logger.log("Dispatching 'load' task:",this.title);
+	this.syncer.syncadaptor.loadTiddler(this.title,function(err,tiddlerFields) {
+		// If there's an error, exit without changing any internal state
+		if(err) {
+			return callback(err);
+		}
+		// Update the info stored about this tiddler
+		if(tiddlerFields) {
+			self.syncer.storeTiddler(tiddlerFields);
+		}
+		// Invoke the callback
+		callback(null);
+	});
+};
+
 exports.Syncer = Syncer;
 
 })();
diff --git a/core/modules/utils/dom/http.js b/core/modules/utils/dom/http.js
index 77cb67c2463..2f6439417ae 100644
--- a/core/modules/utils/dom/http.js
+++ b/core/modules/utils/dom/http.js
@@ -22,6 +22,7 @@ A quick and dirty HTTP function; to be refactored later. Options are:
 */
 exports.httpRequest = function(options) {
 	var type = options.type || "GET",
+		url = options.url,
 		headers = options.headers || {accept: "application/json"},
 		returnProp = options.returnProp || "responseText",
 		request = new XMLHttpRequest(),
@@ -36,7 +37,11 @@ exports.httpRequest = function(options) {
 			$tw.utils.each(options.data,function(dataItem,dataItemTitle) {
 				results.push(dataItemTitle + "=" + encodeURIComponent(dataItem));
 			});
-			data = results.join("&");
+			if(type === "GET" || type === "HEAD") {
+				url += "?" + results.join("&");
+			} else {
+				data = results.join("&");
+			}
 		}
 	}
 	// Set up the state change handler
@@ -52,7 +57,7 @@ exports.httpRequest = function(options) {
 		}
 	};
 	// Make the request
-	request.open(type,options.url,true);
+	request.open(type,url,true);
 	if(headers) {
 		$tw.utils.each(headers,function(header,headerTitle,object) {
 			request.setRequestHeader(headerTitle,header);
diff --git a/core/modules/utils/logger.js b/core/modules/utils/logger.js
index f194d78b315..b3981986dbf 100644
--- a/core/modules/utils/logger.js
+++ b/core/modules/utils/logger.js
@@ -22,15 +22,42 @@ function Logger(componentName,options) {
 	this.componentName = componentName || "";
 	this.colour = options.colour || "white";
 	this.enable = "enable" in options ? options.enable : true;
+	this.save = "save" in options ? options.save : true;
+	this.saveLimit = options.saveLimit || 100 * 1024;
+	this.saveBufferLogger = this;
+	this.buffer = "";
+	this.alertCount = 0;
 }
 
+Logger.prototype.setSaveBuffer = function(logger) {
+	this.saveBufferLogger = logger;
+};
+
 /*
 Log a message
 */
 Logger.prototype.log = function(/* args */) {
-	if(this.enable && console !== undefined && console.log !== undefined) {
-		return Function.apply.call(console.log, console, [$tw.utils.terminalColour(this.colour),this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0)).concat($tw.utils.terminalColour()));
-	}
+	var self = this;
+	if(this.enable) {
+		if(this.saveBufferLogger.save) {
+			this.saveBufferLogger.buffer += $tw.utils.formatDateString(new Date(),"YYYY MM DD 0hh:0mm:0ss.0XXX") + ":";
+			$tw.utils.each(Array.prototype.slice.call(arguments,0),function(arg,index) {
+				self.saveBufferLogger.buffer += " " + arg;
+			});
+			this.saveBufferLogger.buffer += "\n";
+			this.saveBufferLogger.buffer = this.saveBufferLogger.buffer.slice(-this.saveBufferLogger.saveLimit);			
+		}
+		if(console !== undefined && console.log !== undefined) {
+			return Function.apply.call(console.log, console, [$tw.utils.terminalColour(this.colour),this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0)).concat($tw.utils.terminalColour()));
+		}
+	} 
+};
+
+/*
+Read the message buffer
+*/
+Logger.prototype.getBuffer = function() {
+	return this.saveBufferLogger.buffer;
 };
 
 /*
@@ -70,6 +97,7 @@ Logger.prototype.alert = function(/* args */) {
 					component: this.componentName
 				};
 				existingCount = 0;
+				this.alertCount += 1;
 			}
 			alertFields.modified = new Date();
 			if(++existingCount > 1) {
@@ -87,6 +115,22 @@ Logger.prototype.alert = function(/* args */) {
 	}
 };
 
+/*
+Clear outstanding alerts
+*/
+Logger.prototype.clearAlerts = function() {
+	var self = this;
+	if($tw.browser && this.alertCount > 0) {
+		$tw.utils.each($tw.wiki.getTiddlersWithTag(ALERT_TAG),function(title) {
+			var tiddler = $tw.wiki.getTiddler(title);
+			if(tiddler.fields.component === self.componentName) {
+				$tw.wiki.deleteTiddler(title);
+			}
+		});
+		this.alertCount = 0;
+	}
+};
+
 exports.Logger = Logger;
 
 })();
diff --git a/core/modules/utils/utils.js b/core/modules/utils/utils.js
index 2495be49fa5..7787783e5c9 100644
--- a/core/modules/utils/utils.js
+++ b/core/modules/utils/utils.js
@@ -779,4 +779,22 @@ exports.strEndsWith = function(str,ending,position) {
 	}
 };
 
+/*
+Return system information useful for debugging
+*/
+exports.getSystemInfo = function(str,ending,position) {
+	var results = [],
+		save = function(desc,value) {
+			results.push(desc + ": " + value);
+		};
+	if($tw.browser) {
+		save("User Agent",navigator.userAgent);
+		save("Online Status",window.navigator.onLine);
+	}
+	if($tw.node) {
+		save("Node Version",process.version);
+	}
+	return results.join("\n");
+};
+
 })();
diff --git a/core/modules/wiki.js b/core/modules/wiki.js
index fc8b42eda40..2adfb0ef307 100755
--- a/core/modules/wiki.js
+++ b/core/modules/wiki.js
@@ -1233,9 +1233,9 @@ exports.getTiddlerText = function(title,defaultText) {
 	if(!tiddler) {
 		return defaultText;
 	}
-	if(tiddler.fields.text !== undefined) {
+	if(!tiddler.hasField("_is_skinny")) {
 		// Just return the text if we've got it
-		return tiddler.fields.text;
+		return tiddler.fields.text || "";
 	} else {
 		// Tell any listeners about the need to lazily load this tiddler
 		this.dispatchEvent("lazyLoad",title);
diff --git a/core/templates/html-div-skinny-tiddler.tid b/core/templates/html-div-skinny-tiddler.tid
new file mode 100644
index 00000000000..eaf388605e1
--- /dev/null
+++ b/core/templates/html-div-skinny-tiddler.tid
@@ -0,0 +1,9 @@
+title: $:/core/templates/html-div-skinny-tiddler
+
+<!--
+
+This template is a variant of $:/core/templates/html-div-tiddler used for saving skinny tiddlers (with no text field)
+
+-->`<div`<$fields template=' $name$="$encoded_value$"'></$fields>`>
+<pre></pre>
+</div>`
diff --git a/core/templates/save-lazy-all.tid b/core/templates/save-lazy-all.tid
index 5f9220e192a..bf7f9f606a8 100644
--- a/core/templates/save-lazy-all.tid
+++ b/core/templates/save-lazy-all.tid
@@ -3,4 +3,7 @@ title: $:/core/save/lazy-all
 \define saveTiddlerFilter()
 [is[system]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] 
 \end
+\define skinnySaveTiddlerFilter()
+[!is[system]]
+\end
 {{$:/core/templates/tiddlywiki5.html}}
diff --git a/core/templates/save-lazy-images.tid b/core/templates/save-lazy-images.tid
index ff3204729c8..62334f0db32 100644
--- a/core/templates/save-lazy-images.tid
+++ b/core/templates/save-lazy-images.tid
@@ -3,4 +3,7 @@ title: $:/core/save/lazy-images
 \define saveTiddlerFilter()
 [is[tiddler]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] -[!is[system]is[image]] +[sort[title]] 
 \end
+\define skinnySaveTiddlerFilter()
+[is[image]]
+\end
 {{$:/core/templates/tiddlywiki5.html}}
diff --git a/core/templates/store.area.template.html.tid b/core/templates/store.area.template.html.tid
index 3563da318c1..bd9232be369 100644
--- a/core/templates/store.area.template.html.tid
+++ b/core/templates/store.area.template.html.tid
@@ -3,6 +3,7 @@ title: $:/core/templates/store.area.template.html
 <$reveal type="nomatch" state="$:/isEncrypted" text="yes">
 `<div id="storeArea" style="display:none;">`
 <$list filter=<<saveTiddlerFilter>> template="$:/core/templates/html-div-tiddler"/>
+<$list filter={{{ [<skinnySaveTiddlerFilter>] }}} template="$:/core/templates/html-div-skinny-tiddler"/>
 `</div>`
 </$reveal>
 <$reveal type="match" state="$:/isEncrypted" text="yes">
diff --git a/core/ui/AlertTemplate.tid b/core/ui/AlertTemplate.tid
index bcfc3c3fa3a..84b9632f7cf 100644
--- a/core/ui/AlertTemplate.tid
+++ b/core/ui/AlertTemplate.tid
@@ -2,10 +2,12 @@ title: $:/core/ui/AlertTemplate
 
 <div class="tc-alert">
 <div class="tc-alert-toolbar">
-<$button class="tc-btn-invisible"><$action-deletetiddler $tiddler=<<currentTiddler>>/>{{$:/core/images/delete-button}}</$button>
+<$button class="tc-btn-invisible"><$action-deletetiddler $tiddler=<<currentTiddler>>/>{{$:/core/images/cancel-button}}</$button>
 </div>
 <div class="tc-alert-subtitle">
-<$view field="component"/> - <$view field="modified" format="date" template="0hh:0mm:0ss DD MM YYYY"/> <$reveal type="nomatch" state="!!count" text=""><span class="tc-alert-highlight">({{$:/language/Count}}: <$view field="count"/>)</span></$reveal>
+<$wikify name="format" text=<<lingo Tiddler/DateFormat>>>
+<$view field="component"/> - <$view field="modified" format="date" template=<<format>>/> <$reveal type="nomatch" state="!!count" text=""><span class="tc-alert-highlight">({{$:/language/Count}}: <$view field="count"/>)</span></$reveal>
+</$wikify>
 </div>
 <div class="tc-alert-body">
 
diff --git a/core/wiki/config/ServerExternalFiltersDefault.tid b/core/wiki/config/ServerExternalFiltersDefault.tid
new file mode 100644
index 00000000000..7ef93ecf377
--- /dev/null
+++ b/core/wiki/config/ServerExternalFiltersDefault.tid
@@ -0,0 +1,2 @@
+title: $:/config/Server/ExternalFilters/[all[tiddlers]!is[system]sort[title]]
+text: yes
diff --git a/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid b/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid
index 6fdc6af3cfc..6f88fb9a50c 100644
--- a/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid	
+++ b/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid	
@@ -1,5 +1,5 @@
 created: 20130825162100000
-modified: 20140814094907624
+modified: 20200113094126878
 tags: dev moduletypes
 title: SyncAdaptorModules
 type: text/vnd.tiddlywiki
@@ -14,6 +14,8 @@ SyncAdaptorModules encapsulate storage mechanisms that can be used by the SyncMe
 
 SyncAdaptorModules are represented as JavaScript tiddlers with the field `module-type` set to `syncadaptor`.
 
+See [[this pull request|https://github.com/Jermolene/TiddlyWiki5/pull/4373]] for background on the evolution of this API.
+
 ! Exports
 
 The following properties should be exposed via the `exports` object:
@@ -47,12 +49,21 @@ Gets the supplemental information that the adaptor needs to keep track of for a
 
 Returns an object storing any additional information required by the adaptor.
 
+!! `getTiddlerRevision(title)`
+
+Gets the revision ID associated with the specified tiddler title.
+
+|!Parameter |!Description |
+|title |Tiddler title |
+
+Returns a revision ID.
+
 !! `getStatus(callback)`
 
 Retrieves status information from the server. This method is optional.
 
 |!Parameter |!Description |
-|callback |Callback function invoked with parameters `err,isLoggedIn,username` |
+|callback |Callback function invoked with parameters `err,isLoggedIn,username,isReadOnly` |
 
 !! `login(username,password,callback)`
 
@@ -70,16 +81,39 @@ Attempts to logout of the server. This method is optional.
 |!Parameter |!Description |
 |callback |Callback function invoked with parameter `err` |
 
+!! `getUpdatedTiddlers(syncer,callback)`
+
+Retrieves the titles of tiddlers that need to be updated from the server.
+
+This method is optional. If an adaptor doesn't implement it then synchronisation will be unidirectional from the TiddlyWiki store to the adaptor, but not the other way.
+
+The syncer will use the `getUpdatedTiddlers()` method in preference to the `getSkinnyTiddlers()` method.
+
+|!Parameter |!Description |
+|syncer |Reference to the syncer object making the call |
+|callback |Callback function invoked with parameter `err,data` -- see below |
+
+The data provided by the callback is as follows:
+
+```
+{
+modifications: [<array of title>],
+deletions: [<array of title>],
+}
+```
+
 !! `getSkinnyTiddlers(callback)`
 
 Retrieves a list of skinny tiddlers from the server.
 
 This method is optional. If an adaptor doesn't implement it then synchronisation will be unidirectional from the TiddlyWiki store to the adaptor, but not the other way.
 
+The syncer will use the `getUpdatedTiddlers()` method in preference to the `getSkinnyTiddlers()` method.
+
 |!Parameter |!Description |
 |callback |Callback function invoked with parameter `err,tiddlers`, where `tiddlers` is an array of tiddler field objects |
 
-!! `saveTiddler(tiddler,callback,tiddlerInfo)`
+!! `saveTiddler(tiddler,callback)`
 
 Saves a tiddler to the server.
 
@@ -96,11 +130,16 @@ Loads a tiddler from the server.
 |title |Title of tiddler to be retrieved |
 |callback |Callback function invoked with parameter `err,tiddlerFields` |
 
-!! `deleteTiddler(title,callback,tiddlerInfo)`
+!! `deleteTiddler(title,callback,options)`
 
 Delete a tiddler from the server.
 
 |!Parameter |!Description |
 |title |Title of tiddler to be deleted |
 |callback |Callback function invoked with parameter `err` |
+|options |See below |
+
+The options parameter contains the following properties:
+
+|!Property |!Description |
 |tiddlerInfo |The tiddlerInfo maintained by the syncer for this tiddler |
diff --git a/editions/tw5.com/tiddlers/concepts/TiddlerFields.tid b/editions/tw5.com/tiddlers/concepts/TiddlerFields.tid
index 0a0c07c7e6f..ced34345404 100644
--- a/editions/tw5.com/tiddlers/concepts/TiddlerFields.tid
+++ b/editions/tw5.com/tiddlers/concepts/TiddlerFields.tid
@@ -1,5 +1,5 @@
 created: 20130825213300000
-modified: 20191013093910961
+modified: 20191206152031468
 tags: Concepts
 title: TiddlerFields
 type: text/vnd.tiddlywiki
@@ -42,11 +42,13 @@ Other fields used by the core are:
 |`subtitle` |<<lingo subtitle>> |
 |`throttle.refresh` |<<lingo throttle.refresh>> |
 |`toc-link`|<<lingo toc-link>>|
+|`_canonical_uri`|<<lingo _canonical_uri>>|
 
 The TiddlyWebAdaptor uses a few more fields:
 
 |!Field Name |!Description |
 |`bag` |<<lingo bag>> |
 |`revision` |<<lingo revision>> |
+|`_is_skinny` |<<lingo _is_skinny>> |
 
 Details of the fields used in this ~TiddlyWiki are shown in the [[control panel|$:/ControlPanel]] {{$:/core/ui/Buttons/control-panel}} under the <<.controlpanel-tab Info>> tab >> <<.info-tab Advanced>> sub-tab >> Tiddler Fields
diff --git a/editions/tw5.com/tiddlers/webserver/WebServer API_ Get All Tiddlers.tid b/editions/tw5.com/tiddlers/webserver/WebServer API_ Get All Tiddlers.tid
index 98119804ca5..52ca8964f15 100644
--- a/editions/tw5.com/tiddlers/webserver/WebServer API_ Get All Tiddlers.tid	
+++ b/editions/tw5.com/tiddlers/webserver/WebServer API_ Get All Tiddlers.tid	
@@ -1,5 +1,5 @@
 created: 20181002131215403
-modified: 20190903094711346
+modified: 2020031109590546
 tags: [[WebServer API]]
 title: WebServer API: Get All Tiddlers
 type: text/vnd.tiddlywiki
@@ -12,11 +12,23 @@ GET /recipes/default/tiddlers.json
 
 Parameters:
 
-* none
+* ''filter'' - filter identifying tiddlers to be returned (optional, defaults to "[all[tiddlers]!is[system]sort[title]]")
+* ''exclude'' - comma delimited list of fields to excluded from the returned tiddlers (optional, defaults to "text")
 
-Response:
+In order to avoid denial of service attacks with malformed filters in the default configuration the only filter that is accepted is the default filter "[all[tiddlers]!is[system]sort[title]]"; attempts to use any other filter will result in an HTTP 403 error.
+
+To enable a particular filter, create a tiddler with the title "$:/config/Server/ExternalFilters/" concatenated with the filter text, and the text field set to "yes". For example, the TiddlyWeb plugin includes the following shadow tiddler to enable the filter that it requires:
 
+```
+title: $:/config/Server/ExternalFilters/[all[tiddlers]] -[[$:/isEncrypted]] -[prefix[$:/temp/]] -[prefix[$:/status/]]
+text: yes
+```
+
+It is also possible to configure the server to accept any filter by creating a tiddler titled $:/config/Server/AllowAllExternalFilters with the text "yes". This should not be done for public facing servers.
+
+Response:
 
 * 200 OK
 *> `Content-Type: application/json`
 *> Body: array of all non-system tiddlers in [[TiddlyWeb JSON tiddler format]] 
+* 403 Forbidden
diff --git a/editions/tw5.com/tiddlers/webserver/WebServer Parameter_ port.tid b/editions/tw5.com/tiddlers/webserver/WebServer Parameter_ port.tid
index f05da08fca3..bbfee9906a6 100644
--- a/editions/tw5.com/tiddlers/webserver/WebServer Parameter_ port.tid	
+++ b/editions/tw5.com/tiddlers/webserver/WebServer Parameter_ port.tid	
@@ -1,6 +1,6 @@
 caption: port
 created: 20180630180552254
-modified: 20180702155017130
+modified: 20191219123751824
 tags: [[WebServer Parameters]]
 title: WebServer Parameter: port
 type: text/vnd.tiddlywiki
@@ -10,6 +10,7 @@ The [[web server configuration parameter|WebServer Parameters]] ''port'' specifi
 The ''port'' parameter accepts two types of value:
 
 * Numerical values are interpreted as a decimal port number
+** The special value 0 (zero) causes the operating system to assign an available port
 * Non-numeric values are interpreted as an environment variable from which the port should be read
 
 This example configures the server to listen on port 8090:
diff --git a/plugins/tiddlywiki/filesystem/filesystemadaptor.js b/plugins/tiddlywiki/filesystem/filesystemadaptor.js
index a346a66065f..9e0734814ff 100644
--- a/plugins/tiddlywiki/filesystem/filesystemadaptor.js
+++ b/plugins/tiddlywiki/filesystem/filesystemadaptor.js
@@ -26,6 +26,8 @@ function FileSystemAdaptor(options) {
 
 FileSystemAdaptor.prototype.name = "filesystem";
 
+FileSystemAdaptor.prototype.supportsLazyLoading = false;
+
 FileSystemAdaptor.prototype.isReady = function() {
 	// The file system adaptor is always ready
 	return true;
diff --git a/plugins/tiddlywiki/tiddlyweb/ServerControlPanel.tid b/plugins/tiddlywiki/tiddlyweb/ServerControlPanel.tid
deleted file mode 100644
index 9ef1e27afbb..00000000000
--- a/plugins/tiddlywiki/tiddlyweb/ServerControlPanel.tid
+++ /dev/null
@@ -1,20 +0,0 @@
-title: $:/plugins/tiddlywiki/tiddlyweb/ServerControlPanel
-caption: Server
-tags: $:/tags/ControlPanel
-
-<$reveal state="$:/status/IsLoggedIn" type="nomatch" text="yes">
-Log in to ~TiddlyWeb: <$button message="tm-login">Login</$button>
-</$reveal>
-<$reveal state="$:/status/IsLoggedIn" type="match" text="yes">
-Logged in as {{$:/status/UserName}} <$button message="tm-logout">Logout</$button>
-</$reveal>
-
-----
-
-Host configuration: <$edit-text tiddler="$:/config/tiddlyweb/host" tag="input" default=""/>
-
-<blockquote>//for example, `$protocol$//$host$/folder`, where `$protocol$` is replaced by the protocol (typically `http` or `https`), and `$host$` by the host name//</blockquote>
-
-----
-
-<$button message="tm-server-refresh">Refresh</$button> to fetch changes from the server immediately
diff --git a/plugins/tiddlywiki/tiddlyweb/config-tiddlers-filter.tid b/plugins/tiddlywiki/tiddlyweb/config-tiddlers-filter.tid
new file mode 100644
index 00000000000..04bf24613b3
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/config-tiddlers-filter.tid
@@ -0,0 +1,2 @@
+title: $:/config/Server/ExternalFilters/[all[tiddlers]] -[[$:/isEncrypted]] -[prefix[$:/temp/]] -[prefix[$:/status/]]
+text: yes
diff --git a/plugins/tiddlywiki/tiddlyweb/configOfficialPluginLibrary.tid b/plugins/tiddlywiki/tiddlyweb/configOfficialPluginLibrary.tid
new file mode 100644
index 00000000000..9f0e164f414
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/configOfficialPluginLibrary.tid
@@ -0,0 +1,3 @@
+title: $:/config/OfficialPluginLibrary
+
+(This core tiddler is overridden by the tiddlyweb plugin to prevent users from installing official plugins via control panel. Instead they should be installed by editing tiddlywiki.info in the root of the wiki folder)
\ No newline at end of file
diff --git a/plugins/tiddlywiki/tiddlyweb/css-tiddler.tid b/plugins/tiddlywiki/tiddlyweb/css-tiddler.tid
new file mode 100644
index 00000000000..2d7367fa93d
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/css-tiddler.tid
@@ -0,0 +1,7 @@
+title: $:/core/templates/css-tiddler
+
+<!--
+
+This template is used for saving CSS tiddlers as a style tag with data attributes representing the tiddler fields. This version includes the tiddler changecount as the field `revision`.
+
+-->`<style`<$fields template=' data-tiddler-$name$="$encoded_value$"'></$fields>` data-tiddler-revision="`<<changecount>>`" data-tiddler-bag="default" type="text/css">`<$view field="text" format="text" />`</style>`
\ No newline at end of file
diff --git a/plugins/tiddlywiki/tiddlyweb/html-div-skinny-tiddler.tid b/plugins/tiddlywiki/tiddlyweb/html-div-skinny-tiddler.tid
new file mode 100644
index 00000000000..010a603b55c
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/html-div-skinny-tiddler.tid
@@ -0,0 +1,9 @@
+title: $:/core/templates/html-div-skinny-tiddler
+
+<!--
+
+This template is a variant of the tiddlyweb plugin's overridden version of $:/core/templates/html-div-tiddler used for saving skinny tiddlers (with no text field)
+
+-->`<div`<$fields exclude='text revision bag' template=' $name$="$encoded_value$"'></$fields>` revision="`<<changecount>>`" bag="default" _is_skinny="">
+<pre></pre>
+</div>`
diff --git a/plugins/tiddlywiki/tiddlyweb/icon-cloud.tid b/plugins/tiddlywiki/tiddlyweb/icon-cloud.tid
new file mode 100644
index 00000000000..08c5127afae
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/icon-cloud.tid
@@ -0,0 +1,4 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/icon/cloud
+tags: $:/tags/Image
+
+<svg class="tc-image-cloud tc-image-button" width="22pt" height="22pt" viewBox="0 0 128 128"><g><path d="M24 103C10.745 103 0 92.255 0 79c0-9.697 5.75-18.05 14.027-21.836A24.787 24.787 0 0114 56c0-13.255 10.745-24 24-24 1.373 0 2.718.115 4.028.337C48.628 24.2 58.707 19 70 19c19.882 0 36 16.118 36 36v.082c12.319 1.016 22 11.336 22 23.918 0 12.239-9.16 22.337-20.999 23.814L107 103H24z"/><path class="tc-image-cloud-idle" d="M57.929 84.698a6 6 0 01-8.485 0L35.302 70.556a6 6 0 118.485-8.485l9.9 9.9L81.97 43.686a6 6 0 018.485 8.486L57.929 84.698z"/><path class="tc-image-cloud-progress tc-animate-rotate-slow" d="M44.8 40a3.6 3.6 0 100 7.2h2.06A23.922 23.922 0 0040 64c0 13.122 10.531 23.785 23.603 23.997L64 88l.001-7.2c-9.171 0-16.626-7.348-16.798-16.477L47.2 64c0-5.165 2.331-9.786 5.999-12.868L53.2 55.6a3.6 3.6 0 107.2 0v-12a3.6 3.6 0 00-3.6-3.6h-12zM64 40v7.2c9.278 0 16.8 7.522 16.8 16.8 0 5.166-2.332 9.787-6 12.869V72.4a3.6 3.6 0 10-7.2 0v12a3.6 3.6 0 003.6 3.6h12a3.6 3.6 0 100-7.2l-2.062.001A23.922 23.922 0 0088 64c0-13.255-10.745-24-24-24z"/></g></svg>
\ No newline at end of file
diff --git a/plugins/tiddlywiki/tiddlyweb/javascript-tiddler.tid b/plugins/tiddlywiki/tiddlyweb/javascript-tiddler.tid
new file mode 100644
index 00000000000..8478738111b
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/javascript-tiddler.tid
@@ -0,0 +1,7 @@
+title: $:/core/templates/javascript-tiddler
+
+<!--
+
+This template is used for saving JavaScript tiddlers as a script tag with data attributes representing the tiddler fields. This version includes the tiddler changecount as the field `revision`.
+
+-->`<script`<$fields template=' data-tiddler-$name$="$encoded_value$"'></$fields>` data-tiddler-revision="`<<changecount>>`" data-tiddler-bag="default" type="text/javascript">`<$view field="text" format="text" />`</script>`
\ No newline at end of file
diff --git a/plugins/tiddlywiki/tiddlyweb/save-offline.tid b/plugins/tiddlywiki/tiddlyweb/save-offline.tid
index b2bfdbdd171..76f07fe290d 100644
--- a/plugins/tiddlywiki/tiddlyweb/save-offline.tid
+++ b/plugins/tiddlywiki/tiddlyweb/save-offline.tid
@@ -2,6 +2,6 @@ title: $:/plugins/tiddlywiki/tiddlyweb/save/offline
 
 \import [[$:/core/ui/PageMacros]] [all[shadows+tiddlers]tag[$:/tags/Macro]!has[draft.of]]
 \define saveTiddlerFilter()
-[is[tiddler]] -[[$:/boot/boot.css]] -[[$:/HistoryList]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] -[[$:/plugins/tiddlywiki/filesystem]] -[[$:/plugins/tiddlywiki/tiddlyweb]] +[sort[title]] $(publishFilter)$
+[is[tiddler]] -[[$:/boot/boot.css]] -[[$:/HistoryList]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] -[[$:/plugins/tiddlywiki/filesystem]] -[[$:/plugins/tiddlywiki/tiddlyweb]] -[prefix[$:/temp/]] +[sort[title]] $(publishFilter)$
 \end
 {{$:/core/templates/tiddlywiki5.html}}
diff --git a/plugins/tiddlywiki/tiddlyweb/save-wiki-button.tid b/plugins/tiddlywiki/tiddlyweb/save-wiki-button.tid
new file mode 100644
index 00000000000..b0f688349d0
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/save-wiki-button.tid
@@ -0,0 +1,25 @@
+title: $:/core/ui/Buttons/save-wiki
+tags: $:/tags/PageControls
+caption: {{$:/plugins/tiddlywiki/tiddlyweb/icon/cloud}} Server status
+description: Status of synchronisation with server
+
+\define config-title()
+$:/config/PageControlButtons/Visibility/$(listItem)$
+\end
+<$button popup=<<qualify "$:/state/popup/save-wiki">> tooltip="Status of synchronisation with server" aria-label="Server status" class=<<tv-config-toolbar-class>> selectedClass="tc-selected">
+<span class="tc-dirty-indicator">
+<$list filter="[<tv-config-toolbar-icons>match[yes]]">
+{{$:/plugins/tiddlywiki/tiddlyweb/icon/cloud}}
+</$list>
+<$list filter="[<tv-config-toolbar-text>match[yes]]">
+<span class="tc-btn-text"><$text text="Server status"/></span>
+</$list>
+</span>
+</$button>
+<$reveal state=<<qualify "$:/state/popup/save-wiki">> type="popup" position="below" animate="yes">
+<div class="tc-drop-down">
+<$list filter="[all[shadows+tiddlers]tag[$:/tags/SyncerDropdown]!has[draft.of]]" variable="listItem">
+<$transclude tiddler=<<listItem>>/>
+</$list>
+</div>
+</$reveal>
diff --git a/plugins/tiddlywiki/tiddlyweb/styles.tid b/plugins/tiddlywiki/tiddlyweb/styles.tid
new file mode 100644
index 00000000000..5d59fa37923
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/styles.tid
@@ -0,0 +1,40 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/styles
+tags: [[$:/tags/Stylesheet]]
+
+\rules only filteredtranscludeinline transcludeinline macrodef macrocallinline macrocallblock
+
+body.tc-dirty span.tc-dirty-indicator svg {
+	transition: fill 250ms ease-in-out;
+}
+
+body .tc-image-cloud-idle {
+	fill: <<colour background>>;
+	transition: opacity 250ms ease-in-out;
+	opacity: 1;	
+}
+
+body.tc-dirty .tc-image-cloud-idle {
+	opacity: 0;
+}
+
+body .tc-image-cloud-progress {
+	transition: opacity 250ms ease-in-out;
+	transform-origin: 50% 50%;
+	transform: rotate(359deg);
+	animation: animation-rotate-slow 2s infinite linear;
+	fill: <<colour background>>;
+	opacity: 0;
+}
+
+body.tc-dirty .tc-image-cloud-progress {
+	opacity: 1;
+}
+
+@keyframes animation-rotate-slow {
+	from {
+		transform: rotate(0deg);
+	}
+	to {
+		transform: scale(359deg);
+	}
+}
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-copy-logs.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-copy-logs.tid
new file mode 100644
index 00000000000..b141670e687
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-copy-logs.tid
@@ -0,0 +1,6 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/copy-logs
+tags: $:/tags/SyncerDropdown
+
+<$button message="tm-copy-syncer-logs-to-clipboard" class="tc-btn-invisible">
+{{$:/core/images/copy-clipboard}} Copy syncer logs to clipboard
+</$button>
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-login-status.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-login-status.tid
new file mode 100644
index 00000000000..11816f1b47d
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-login-status.tid
@@ -0,0 +1,9 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/login-status
+tags: $:/tags/SyncerDropdown
+
+<$reveal state="$:/status/IsLoggedIn" type="match" text="yes">
+<div class="tc-drop-down-info">
+You are logged in<$reveal state="$:/status/UserName" type="nomatch" text="" default=""> as <strong><$text text={{$:/status/UserName}}/></strong></$reveal><$reveal state="$:/status/IsReadOnly" type="match" text="yes" default="no"> (read-only)</$reveal>
+</div>
+<hr/>
+</$reveal>
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-login.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-login.tid
new file mode 100644
index 00000000000..cdd95f5a654
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-login.tid
@@ -0,0 +1,8 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/login
+tags: $:/tags/SyncerDropdown
+
+<$reveal state="$:/status/IsLoggedIn" type="nomatch" text="yes">
+<$button message="tm-login" class="tc-btn-invisible">
+{{$:/core/images/unlocked-padlock}} Login
+</$button>
+</$reveal>
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-logout.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-logout.tid
new file mode 100644
index 00000000000..358944d1a12
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-logout.tid
@@ -0,0 +1,8 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/logout
+tags: $:/tags/SyncerDropdown
+
+<$reveal state="$:/status/IsLoggedIn" type="match" text="yes">
+<$button message="tm-logout" class="tc-btn-invisible">
+{{$:/core/images/cancel-button}} Logout
+</$button>
+</$reveal>
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-refresh.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-refresh.tid
new file mode 100644
index 00000000000..eeb0ddba2b7
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-refresh.tid
@@ -0,0 +1,9 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/refresh
+tags: $:/tags/SyncerDropdown
+
+<$reveal state="$:/status/IsLoggedIn" type="match" text="yes">
+<$button tooltip="Get latest changes from the server" aria-label="Refresh from server" class="tc-btn-invisible">
+<$action-sendmessage $message="tm-server-refresh"/>
+{{$:/core/images/refresh-button}} <span clas]s="tc-btn-text"><$text text="Get latest changes from the server"/></span>
+</$button>
+</$reveal>
diff --git a/plugins/tiddlywiki/tiddlyweb/syncer-actions-save-snapshot.tid b/plugins/tiddlywiki/tiddlyweb/syncer-actions-save-snapshot.tid
new file mode 100644
index 00000000000..23bb4c914cd
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/syncer-actions-save-snapshot.tid
@@ -0,0 +1,9 @@
+title: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/save-snapshot
+tags: $:/tags/SyncerDropdown
+
+<$button class="tc-btn-invisible">
+<$wikify name="site-title" text={{$:/config/SaveWikiButton/Filename}}>
+<$action-sendmessage $message="tm-download-file" $param={{$:/config/SaveWikiButton/Template}} filename=<<site-title>>/>
+</$wikify>
+{{$:/core/images/download-button}} Save snapshot for offline use
+</$button>
diff --git a/plugins/tiddlywiki/tiddlyweb/tags-syncerdropdown.tid b/plugins/tiddlywiki/tiddlyweb/tags-syncerdropdown.tid
new file mode 100644
index 00000000000..07135a75b0f
--- /dev/null
+++ b/plugins/tiddlywiki/tiddlyweb/tags-syncerdropdown.tid
@@ -0,0 +1,2 @@
+title: $:/tags/SyncerDropdown
+list: $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/login-status $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/login $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/refresh $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/logout $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/save-snapshot $:/plugins/tiddlywiki/tiddlyweb/syncer-actions/copy-logs
diff --git a/plugins/tiddlywiki/tiddlyweb/tiddlywebadaptor.js b/plugins/tiddlywiki/tiddlyweb/tiddlywebadaptor.js
index 4929093240a..5bc4e502db5 100644
--- a/plugins/tiddlywiki/tiddlyweb/tiddlywebadaptor.js
+++ b/plugins/tiddlywiki/tiddlyweb/tiddlywebadaptor.js
@@ -27,6 +27,12 @@ function TiddlyWebAdaptor(options) {
 
 TiddlyWebAdaptor.prototype.name = "tiddlyweb";
 
+TiddlyWebAdaptor.prototype.supportsLazyLoading = true;
+
+TiddlyWebAdaptor.prototype.setLoggerSaveBuffer = function(loggerForSaving) {
+	this.logger.setSaveBuffer(loggerForSaving);
+};
+
 TiddlyWebAdaptor.prototype.isReady = function() {
 	return this.hasStatus;
 };
@@ -50,6 +56,11 @@ TiddlyWebAdaptor.prototype.getTiddlerInfo = function(tiddler) {
 	};
 };
 
+TiddlyWebAdaptor.prototype.getTiddlerRevision = function(title) {
+	var tiddler = this.wiki.getTiddler(title);
+	return tiddler.fields.revision;
+};
+
 /*
 Get the current status of the TiddlyWeb connection
 */
@@ -147,6 +158,9 @@ TiddlyWebAdaptor.prototype.getSkinnyTiddlers = function(callback) {
 	var self = this;
 	$tw.utils.httpRequest({
 		url: this.host + "recipes/" + this.recipe + "/tiddlers.json",
+		data: {
+			filter: "[all[tiddlers]] -[[$:/isEncrypted]] -[prefix[$:/temp/]] -[prefix[$:/status/]]"
+		},
 		callback: function(err,data) {
 			// Check for errors
 			if(err) {
@@ -220,7 +234,7 @@ TiddlyWebAdaptor.prototype.deleteTiddler = function(title,callback,options) {
 		return callback(null);
 	}
 	// If we don't have a bag it means that the tiddler hasn't been seen by the server, so we don't need to delete it
-	var bag = options.tiddlerInfo.adaptorInfo.bag;
+	var bag = options.tiddlerInfo.adaptorInfo && options.tiddlerInfo.adaptorInfo.bag;
 	if(!bag) {
 		return callback(null);
 	}
diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 91e2e6b61a0..2541938c143 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -1450,6 +1450,10 @@ html body.tc-body.tc-single-tiddler-window {
 	fill: <<colour foreground>>;
 }
 
+.tc-drop-down .tc-drop-down-info {
+	padding-left: 14px;
+}
+
 .tc-drop-down p {
 	padding: 0 14px 0 14px;
 }
@@ -1978,24 +1982,26 @@ html body.tc-body.tc-single-tiddler-window {
 
 .tc-alerts {
 	position: fixed;
-	top: 0;
+	top: 28px;
 	left: 0;
-	max-width: 500px;
+	right: 0;
+	max-width: 50%;
 	z-index: 20000;
 }
 
 .tc-alert {
 	position: relative;
-	margin: 28px;
-	padding: 14px 14px 14px 14px;
-	border: 2px solid <<colour alert-border>>;
+	margin: 14px;
+	padding: 7px;
+	border: 1px solid <<colour alert-border>>;
 	background-color: <<colour alert-background>>;
 }
 
 .tc-alert-toolbar {
 	position: absolute;
-	top: 14px;
-	right: 14px;
+	top: 7px;
+	right: 7px;
+    line-height: 0;
 }
 
 .tc-alert-toolbar svg {
@@ -2005,6 +2011,12 @@ html body.tc-body.tc-single-tiddler-window {
 .tc-alert-subtitle {
 	color: <<colour alert-muted-foreground>>;
 	font-weight: bold;
+    font-size: 0.8em;
+    margin-bottom: 0.5em;
+}
+
+.tc-alert-body > p {
+	margin: 0;
 }
 
 .tc-alert-highlight {