diff --git a/core/modules/macros/reveal.js b/core/modules/macros/reveal.js
new file mode 100644
index 000000000..9bcdfde76
--- /dev/null
+++ b/core/modules/macros/reveal.js
@@ -0,0 +1,88 @@
+/*\
+title: $:/core/modules/macros/reveal.js
+type: application/javascript
+module-type: macro
+
+The reveal macro shows or hides content according to the value of the text in a specified tiddler.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports.info = {
+	name: "reveal",
+	params: {
+		state: {byPos: 0, type: "tiddler"},
+		qualifyTiddlerTitles: {byName: true, type: "text"},
+		"default": {byName: true, type: "text"},
+		on: {byName: true, type: "text"},
+		"class": {byName: true, type: "text"}
+	}
+};
+
+exports.getOpenState = function() {
+	if(this.stateTitle) {
+		var on = this.params.on || "open";
+		var stateTiddler = this.wiki.getTiddler(this.stateTitle);
+		if(stateTiddler) {
+			return stateTiddler.fields.text.trim() === on;
+		}
+	}
+	if(this.hasParameter("default")) {
+		return this.params["default"] === "open";
+	}
+	return false;
+};
+
+exports.executeMacro = function() {
+	this.stateTitle = this.params.state;
+	if(this.hasParameter("qualifyTiddlerTitles")) {
+		this.stateTitle = "(" + this.parents.join(",") + "," + this.tiddlerTitle + ")" + this.stateTitle;
+	}
+	this.isOpen = this.getOpenState();
+	var attributes = {
+		"class": ["tw-reveal"]
+	};
+	if(this.hasParameter("class")) {
+		attributes["class"].push(this.params["class"]);
+	}
+	if(this.classes) {
+		$tw.utils.pushTop(attributes["class"],this.classes);
+	}
+	attributes.style = {display: this.isOpen ? "block" : "none"};
+	var child = $tw.Tree.Element("div",attributes,this.isOpen ? this.content : []);
+	child.execute(this.parents,this.tiddlerTitle);
+	return child;
+};
+
+exports.refreshInDom = function(changes) {
+	var needChildrenRefresh = true, // Avoid refreshing the children nodes if we don't need to
+		t;
+	// If the state tiddler has changed then reset the open state
+	if($tw.utils.hop(changes,this.stateTitle)) {
+		this.isOpen = this.getOpenState();
+	}
+	// Render the children if we're open and we don't have any children yet
+	if(this.isOpen && this.child.children.length === 0) {
+		// Install the children and execute them
+		this.child.children = this.content;
+		for(t=0; t<this.child.children.length; t++) {
+			this.child.children[t].execute(this.parents,this.tiddlerTitle);
+			this.child.children[t].renderInDom(this.child.domNode);
+		}
+		needChildrenRefresh = false; // Don't refresh the children if we've just created them
+	}
+	// Set the visibility of the children
+	this.child.domNode.style.display = this.isOpen ? "block" : "none";
+	// Refresh the children
+	if(needChildrenRefresh) {
+		for(t=0; t<this.child.children.length; t++) {
+			this.child.children[t].refreshInDom(changes);
+		}
+	}
+};
+
+})();