diff --git a/src/lib/path.html b/src/lib/path.html
new file mode 100644
index 0000000000..25665d966b
--- /dev/null
+++ b/src/lib/path.html
@@ -0,0 +1,53 @@
+<!--
+@license
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<script>
+
+  Polymer.Path = {
+
+    head: function(path) {
+      var dotIndex = path.indexOf('.');
+      if (dotIndex === -1) {
+        return path;
+      }
+      return path.slice(0, dotIndex);
+    },
+
+    isDeep: function(path) {
+      return path.indexOf('.') !== -1;
+    },
+
+    // Given `base` is `foo.bar`, `foo` is an ancestor, `foo.bar` is not
+    isAncestor: function(base, path) {
+      //     base.startsWith(path + '.');
+      return base.indexOf(path + '.') === 0;
+    },
+
+    // Given `base` is `foo.bar`, `foo.bar.baz` is an descendant
+    isDescendant: function(base, path) {
+      //     path.startsWith(base + '.');
+      return path.indexOf(base + '.') === 0;
+    },
+
+    // can be read as:  from  to       path
+    translate: function(base, newBase, path) {
+      // Defense?
+      return newBase + path.slice(base.length);
+    },
+
+    matches: function(base, wildcard, path) {
+      return (base === path) ||
+             this.isAncestor(base, path) ||
+             (Boolean(wildcard) && this.isDescendant(base, path));
+    }
+
+
+  };
+
+</script>
diff --git a/test/runner.html b/test/runner.html
index b51d438969..ef4730d533 100644
--- a/test/runner.html
+++ b/test/runner.html
@@ -44,6 +44,7 @@
       'unit/bind.html',
       'unit/bind.html?dom=shadow',
       'unit/notify-path.html',
+      'unit/path.html',
       'unit/array-selector.html',
       'unit/events.html',
       'unit/gestures.html',
diff --git a/test/unit/path.html b/test/unit/path.html
new file mode 100644
index 0000000000..31dd2e0227
--- /dev/null
+++ b/test/unit/path.html
@@ -0,0 +1,96 @@
+<!doctype html>
+<!--
+@license
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<html>
+<head>
+  <meta charset="utf-8">
+  <script src="../../../webcomponentsjs/webcomponents-lite.js"></script>
+  <script src="../../../web-component-tester/browser.js"></script>
+  <link rel="import" href="../../src/polymer-lib.html">
+  <link rel="import" href="../../src/lib/path.html">
+</head>
+<body>
+
+<script>
+  suite('path utilities', function() {
+
+    var Path;
+
+    setup(function() {
+      Path = Polymer.Path;
+    });
+
+    test('head()', function() {
+      assert.equal(Path.head('foo'), 'foo');
+      assert.equal(Path.head('foo.bar'), 'foo');
+    });
+
+    test('isDeep()', function() {
+      assert.equal(Path.isDeep('foo'), false);
+      assert.equal(Path.isDeep('foo.bar'), true);
+    });
+
+    test('isAncestor()', function() {
+      assert.equal(Path.isAncestor('foo.bar', 'foo'),          true);
+
+      assert.equal(Path.isAncestor('foo.bar', 'foo.bar'),      false);
+      assert.equal(Path.isAncestor('foo.bar', 'foo.baz'),      false);
+      assert.equal(Path.isAncestor('foo.bar', 'fooz'),         false);
+      assert.equal(Path.isAncestor('foo.bar', 'bar'),          false);
+      assert.equal(Path.isAncestor('foo.bar', 'foo.bars'),     false);
+      assert.equal(Path.isAncestor('foo.bar', 'foo.bar.quux'), false);
+
+
+      assert.equal(Path.isAncestor('foo.bar.baz', 'foo'),      true);
+      assert.equal(Path.isAncestor('foo.bar.baz', 'foo.bar'),  true);
+
+      assert.equal(Path.isAncestor('foo.bar.baz', 'foo.baz'),  false);
+      assert.equal(Path.isAncestor('foo.bar.baz', 'foo.bars'), false);
+    });
+
+    test('isDescendant()', function() {
+      assert.equal(Path.isDescendant('foo.bar', 'foo.bar.baz'),  true);
+      assert.equal(Path.isDescendant('foo.bar', 'foo.bar'),      false);
+      assert.equal(Path.isDescendant('foo.bar', 'foo.bars'),     false);
+      assert.equal(Path.isDescendant('foo.bar', 'foo'),          false);
+      assert.equal(Path.isDescendant('foo.bar', 'bar'),          false);
+
+      assert.equal(Path.isDescendant('foo', 'foo.bar'), true);
+      assert.equal(Path.isDescendant('foo', 'foo'),     false);
+    });
+
+    test('translate()', function() {
+      assert.equal(Path.translate('foo', 'baz', 'foo.bar'),
+                   'baz.bar');
+      assert.equal(Path.translate('foo', 'quux', 'foo.bar.baz'),
+                   'quux.bar.baz');
+      assert.equal(Path.translate('foo.bar', 'quux', 'foo.bar.baz'),
+                   'quux.baz');
+    });
+
+    test('matches()', function() {
+      assert.equal(Path.matches('foo.bar', false, 'foo'),         true);
+      assert.equal(Path.matches('foo.bar', false, 'foo.bar'),     true);
+      assert.equal(Path.matches('foo.bar', false, 'fooz'),        false);
+      assert.equal(Path.matches('foo.bar', false, 'foo.baz'),     false);
+      assert.equal(Path.matches('foo.bar', false, 'foo.bars'),    false);
+      assert.equal(Path.matches('foo.bar', false, 'foo.bar.baz'), false);
+
+
+      // deep wildcard matches
+      assert.equal(Path.matches('foo.bar', true, 'foo'),          true);
+      assert.equal(Path.matches('foo.bar', true, 'foo.bar'),      true);
+      assert.equal(Path.matches('foo.bar', true, 'foo.bar.baz'),  true);
+      assert.equal(Path.matches('foo.bar', true, 'fooz'),         false);
+      assert.equal(Path.matches('foo.bar', true, 'foo.baz'),      false);
+      assert.equal(Path.matches('foo.bar', true, 'foo.bars'),     false);
+    });
+  });
+</script>
