diff --git a/package.json b/package.json
index b3a7b4362f..0636008e2d 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
     "codecov": "codecov",
     "precodecov": "npm run coverage",
     "lint": "eslint src test/*.js",
-    "build": "node src/shared/_build.js && rollup -c",
+    "build": "node src/shared/_build.js && rollup -c && rollup -c rollup.store.config.js",
     "prepare": "npm run build",
     "dev": "node src/shared/_build.js && rollup -c -w",
     "pretest": "npm run build",
diff --git a/rollup.store.config.js b/rollup.store.config.js
new file mode 100644
index 0000000000..a3e4f395c6
--- /dev/null
+++ b/rollup.store.config.js
@@ -0,0 +1,9 @@
+export default {
+	input: 'store.js',
+	output: {
+		file: 'store.umd.js',
+		format: 'umd',
+		name: 'svelte',
+		extend: true
+	}
+};
diff --git a/store.umd.js b/store.umd.js
new file mode 100644
index 0000000000..50c7aa7469
--- /dev/null
+++ b/store.umd.js
@@ -0,0 +1,232 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+	typeof define === 'function' && define.amd ? define(['exports'], factory) :
+	(factory((global.svelte = global.svelte || {})));
+}(this, (function (exports) { 'use strict';
+
+function assign(target) {
+	var k,
+		source,
+		i = 1,
+		len = arguments.length;
+	for (; i < len; i++) {
+		source = arguments[i];
+		for (k in source) target[k] = source[k];
+	}
+
+	return target;
+}
+
+function blankObject() {
+	return Object.create(null);
+}
+
+function differs(a, b) {
+	return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+function dispatchObservers(component, group, changed, newState, oldState) {
+	for (var key in group) {
+		if (!changed[key]) continue;
+
+		var newValue = newState[key];
+		var oldValue = oldState[key];
+
+		var callbacks = group[key];
+		if (!callbacks) continue;
+
+		for (var i = 0; i < callbacks.length; i += 1) {
+			var callback = callbacks[i];
+			if (callback.__calling) continue;
+
+			callback.__calling = true;
+			callback.call(component, newValue, oldValue);
+			callback.__calling = false;
+		}
+	}
+}
+
+function get(key) {
+	return key ? this._state[key] : this._state;
+}
+
+function observe(key, callback, options) {
+	var group = options && options.defer
+		? this._observers.post
+		: this._observers.pre;
+
+	(group[key] || (group[key] = [])).push(callback);
+
+	if (!options || options.init !== false) {
+		callback.__calling = true;
+		callback.call(this, this._state[key]);
+		callback.__calling = false;
+	}
+
+	return {
+		cancel: function() {
+			var index = group[key].indexOf(callback);
+			if (~index) group[key].splice(index, 1);
+		}
+	};
+}
+
+function Store(state) {
+	this._observers = { pre: blankObject(), post: blankObject() };
+	this._changeHandlers = [];
+	this._dependents = [];
+
+	this._computed = blankObject();
+	this._sortedComputedProperties = [];
+
+	this._state = assign({}, state);
+}
+
+assign(Store.prototype, {
+	_add: function(component, props) {
+		this._dependents.push({
+			component: component,
+			props: props
+		});
+	},
+
+	_init: function(props) {
+		var state = {};
+		for (var i = 0; i < props.length; i += 1) {
+			var prop = props[i];
+			state['$' + prop] = this._state[prop];
+		}
+		return state;
+	},
+
+	_remove: function(component) {
+		var i = this._dependents.length;
+		while (i--) {
+			if (this._dependents[i].component === component) {
+				this._dependents.splice(i, 1);
+				return;
+			}
+		}
+	},
+
+	_sortComputedProperties: function() {
+		var computed = this._computed;
+		var sorted = this._sortedComputedProperties = [];
+		var cycles;
+		var visited = blankObject();
+
+		function visit(key) {
+			if (cycles[key]) {
+				throw new Error('Cyclical dependency detected');
+			}
+
+			if (visited[key]) return;
+			visited[key] = true;
+
+			var c = computed[key];
+
+			if (c) {
+				cycles[key] = true;
+				c.deps.forEach(visit);
+				sorted.push(c);
+			}
+		}
+
+		for (var key in this._computed) {
+			cycles = blankObject();
+			visit(key);
+		}
+	},
+
+	compute: function(key, deps, fn) {
+		var store = this;
+		var value;
+
+		var c = {
+			deps: deps,
+			update: function(state, changed, dirty) {
+				var values = deps.map(function(dep) {
+					if (dep in changed) dirty = true;
+					return state[dep];
+				});
+
+				if (dirty) {
+					var newValue = fn.apply(null, values);
+					if (differs(newValue, value)) {
+						value = newValue;
+						changed[key] = true;
+						state[key] = value;
+					}
+				}
+			}
+		};
+
+		c.update(this._state, {}, true);
+
+		this._computed[key] = c;
+		this._sortComputedProperties();
+	},
+
+	get: get,
+
+	observe: observe,
+
+	onchange: function(callback) {
+		this._changeHandlers.push(callback);
+		return {
+			cancel: function() {
+				var index = this._changeHandlers.indexOf(callback);
+				if (~index) this._changeHandlers.splice(index, 1);
+			}
+		};
+	},
+
+	set: function(newState) {
+		var oldState = this._state,
+			changed = this._changed = {},
+			dirty = false;
+
+		for (var key in newState) {
+			if (this._computed[key]) throw new Error("'" + key + "' is a read-only property");
+			if (differs(newState[key], oldState[key])) changed[key] = dirty = true;
+		}
+		if (!dirty) return;
+
+		this._state = assign({}, oldState, newState);
+
+		for (var i = 0; i < this._sortedComputedProperties.length; i += 1) {
+			this._sortedComputedProperties[i].update(this._state, changed);
+		}
+
+		for (var i = 0; i < this._changeHandlers.length; i += 1) {
+			this._changeHandlers[i](this._state, changed);
+		}
+
+		dispatchObservers(this, this._observers.pre, changed, this._state, oldState);
+
+		var dependents = this._dependents.slice(); // guard against mutations
+		for (var i = 0; i < dependents.length; i += 1) {
+			var dependent = dependents[i];
+			var componentState = {};
+			dirty = false;
+
+			for (var j = 0; j < dependent.props.length; j += 1) {
+				var prop = dependent.props[j];
+				if (prop in changed) {
+					componentState['$' + prop] = this._state[prop];
+					dirty = true;
+				}
+			}
+
+			if (dirty) dependent.component.set(componentState);
+		}
+
+		dispatchObservers(this, this._observers.post, changed, this._state, oldState);
+	}
+});
+
+exports.Store = Store;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+})));