diff --git a/modules/helpers/Path.js b/modules/helpers/Path.js
index 19d6f26a8f..052ee07d89 100644
--- a/modules/helpers/Path.js
+++ b/modules/helpers/Path.js
@@ -1,112 +1,117 @@
 var invariant = require('react/lib/invariant');
-var copyProperties = require('react/lib/copyProperties');
-var qs = require('querystring');
-var URL = require('./URL');
+var merge = require('qs/lib/utils').merge;
+var qs = require('qs');
 
-var paramMatcher = /((?::[a-z_$][a-z0-9_$]*)|\*)/ig;
-var queryMatcher = /\?(.+)/;
-
-function getParamName(pathSegment) {
-  return pathSegment === '*' ? 'splat' : pathSegment.substr(1);
+function encodeURL(url) {
+  return encodeURIComponent(url).replace(/%20/g, '+');
 }
 
-var _compiledPatterns = {};
+function decodeURL(url) {
+  return decodeURIComponent(url.replace(/\+/g, ' '));
+}
 
-function compilePattern(pattern) {
-  if (_compiledPatterns[pattern])
-    return _compiledPatterns[pattern];
+function encodeURLPath(path) {
+  return String(path).split('/').map(encodeURL).join('/');
+}
 
-  var compiled = _compiledPatterns[pattern] = {};
-  var paramNames = compiled.paramNames = [];
+var paramMatcher = /:([a-zA-Z_$][a-zA-Z0-9_$]*)|[*.()\[\]\\+|{}^$]/g;
+var queryMatcher = /\?(.+)/;
 
-  var source = pattern.replace(paramMatcher, function (match, pathSegment) {
-    paramNames.push(getParamName(pathSegment));
-    return pathSegment === '*' ? '(.*?)' : '([^/?#]+)';
-  });
+var _compiledPatterns = {};
 
-  compiled.matcher = new RegExp('^' + source + '$', 'i');
+function compilePattern(pattern) {
+  if (!(pattern in _compiledPatterns)) {
+    var paramNames = [];
+    var source = pattern.replace(paramMatcher, function (match, paramName) {
+      if (paramName) {
+        paramNames.push(paramName);
+        return '([^./?#]+)';
+      } else if (match === '*') {
+        paramNames.push('splat');
+        return '(.*?)';
+      } else {
+        return '\\' + match;
+      }
+    });
 
-  return compiled;
-}
+    _compiledPatterns[pattern] = {
+      matcher: new RegExp('^' + source + '$', 'i'),
+      paramNames: paramNames
+    };
+  }
 
-function isDynamicPattern(pattern) {
-  return pattern.indexOf(':') !== -1 || pattern.indexOf('*') !== -1;
+  return _compiledPatterns[pattern];
 }
 
 var Path = {
 
+  /**
+   * Returns an array of the names of all parameters in the given pattern.
+   */
+  extractParamNames: function (pattern) {
+    return compilePattern(pattern).paramNames;
+  },
+
   /**
    * Extracts the portions of the given URL path that match the given pattern
    * and returns an object of param name => value pairs. Returns null if the
    * pattern does not match the given path.
    */
   extractParams: function (pattern, path) {
-    if (!pattern)
-      return null;
-
-    if (!isDynamicPattern(pattern)) {
-      if (pattern === URL.decode(path))
-        return {}; // No dynamic segments, but the paths match.
-
-      return null;
-    }
-
-    var compiled = compilePattern(pattern);
-    var match = URL.decode(path).match(compiled.matcher);
+    var object = compilePattern(pattern);
+    var match = decodeURL(path).match(object.matcher);
 
     if (!match)
       return null;
 
     var params = {};
 
-    compiled.paramNames.forEach(function (paramName, index) {
+    object.paramNames.forEach(function (paramName, index) {
       params[paramName] = match[index + 1];
     });
 
     return params;
   },
 
-  /**
-   * Returns an array of the names of all parameters in the given pattern.
-   */
-  extractParamNames: function (pattern) {
-    if (!pattern)
-      return [];
-    return compilePattern(pattern).paramNames;
-  },
-
   /**
    * Returns a version of the given route path with params interpolated. Throws
    * if there is a dynamic segment of the route path for which there is no param.
    */
   injectParams: function (pattern, params) {
-    if (!pattern)
-      return null;
-
-    if (!isDynamicPattern(pattern))
-      return pattern;
-
     params = params || {};
 
-    return pattern.replace(paramMatcher, function (match, pathSegment) {
-      var paramName = getParamName(pathSegment);
+    var splatIndex = 0;
+
+    return pattern.replace(paramMatcher, function (match, paramName) {
+      paramName = paramName || 'splat';
 
       invariant(
         params[paramName] != null,
         'Missing "' + paramName + '" parameter for path "' + pattern + '"'
       );
 
-      // Preserve forward slashes.
-      return String(params[paramName]).split('/').map(URL.encode).join('/');
+      var segment;
+      if (paramName === 'splat' && Array.isArray(params[paramName])) {
+        segment = params[paramName][splatIndex++];
+
+        invariant(
+          segment != null,
+          'Missing splat # ' + splatIndex + ' for path "' + pattern + '"'
+        );
+      } else {
+        segment = params[paramName];
+      }
+
+      return encodeURLPath(segment);
     });
   },
 
   /**
-   * Returns an object that is the result of parsing any query string contained in
-   * the given path, null if the path contains no query string.
+   * Returns an object that is the result of parsing any query string contained
+   * in the given path, null if the path contains no query string.
    */
   extractQuery: function (path) {
-    var match = path.match(queryMatcher);
+    var match = decodeURL(path).match(queryMatcher);
     return match && qs.parse(match[1]);
   },
 
@@ -118,14 +123,14 @@ var Path = {
   },
 
   /**
-   * Returns a version of the given path with the parameters in the given query
-   * added to the query string.
+   * Returns a version of the given path with the parameters in the given
+   * query merged into the query string.
    */
   withQuery: function (path, query) {
     var existingQuery = Path.extractQuery(path);
 
     if (existingQuery)
-      query = query ? copyProperties(existingQuery, query) : existingQuery;
+      query = query ? merge(existingQuery, query) : existingQuery;
 
     var queryString = query && qs.stringify(query);
 
diff --git a/modules/helpers/URL.js b/modules/helpers/URL.js
deleted file mode 100644
index 18b9f8f4f9..0000000000
--- a/modules/helpers/URL.js
+++ /dev/null
@@ -1,22 +0,0 @@
-var urlEncodedSpaceRE = /\+/g;
-var encodedSpaceRE = /%20/g;
-
-var URL = {
-
-  /* These functions were copied from the https://github.com/cujojs/rest source, MIT licensed */
-
-  decode: function (str) {
-    // spec says space should be encoded as '+'
-    str = str.replace(urlEncodedSpaceRE, ' ');
-    return decodeURIComponent(str);
-  },
-
-  encode: function (str) {
-    str = encodeURIComponent(str);
-    // spec says space should be encoded as '+'
-    return str.replace(encodedSpaceRE, '+');
-  }
-
-};
-
-module.exports = URL;
diff --git a/package.json b/package.json
index f513d6e52f..fbaca1a1ac 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
   "dependencies": {
     "es6-promise": "^1.0.0",
     "events": "^1.0.1",
-    "querystring": "^0.2.0"
+    "qs": "^1.2.2"
   },
   "keywords": [
     "react",
diff --git a/specs/Path.spec.js b/specs/Path.spec.js
index b0cf65378d..79f2a0be10 100644
--- a/specs/Path.spec.js
+++ b/specs/Path.spec.js
@@ -1,6 +1,26 @@
 require('./helper');
 var Path = require('../modules/helpers/Path');
 
+describe('Path.extractParamNames', function () {
+  describe('when a pattern contains no dynamic segments', function () {
+    it('returns an empty array', function () {
+      expect(Path.extractParamNames('a/b/c')).toEqual([]);
+    });
+  });
+
+  describe('when a pattern contains :a and :b dynamic segments', function () {
+    it('returns the correct names', function () {
+      expect(Path.extractParamNames('/comments/:a/:b/edit')).toEqual([ 'a', 'b' ]);
+    });
+  });
+
+  describe('when a pattern has a *', function () {
+    it('uses the name "splat"', function () {
+      expect(Path.extractParamNames('/files/*.jpg')).toEqual([ 'splat' ]);
+    });
+  });
+});
+
 describe('Path.extractParams', function () {
   describe('when a pattern does not have dynamic segments', function () {
     var pattern = 'a/b/c';
@@ -19,11 +39,11 @@ describe('Path.extractParams', function () {
   });
 
   describe('when a pattern has dynamic segments', function () {
-    var pattern = 'comments/:id/edit';
+    var pattern = 'comments/:id.:ext/edit';
 
     describe('and the path matches', function () {
       it('returns an object with the params', function () {
-        expect(Path.extractParams(pattern, 'comments/abc/edit')).toEqual({ id: 'abc' });
+        expect(Path.extractParams(pattern, 'comments/abc.js/edit')).toEqual({ id: 'abc', ext: 'js' });
       });
     });
 
@@ -35,7 +55,7 @@ describe('Path.extractParams', function () {
 
     describe('and the path matches with a segment containing a .', function () {
       it('returns an object with the params', function () {
-        expect(Path.extractParams(pattern, 'comments/foo.bar/edit')).toEqual({ id: 'foo.bar' });
+        expect(Path.extractParams(pattern, 'comments/foo.bar/edit')).toEqual({ id: 'foo', ext: 'bar' });
       });
     });
   });
@@ -73,38 +93,37 @@ describe('Path.extractParams', function () {
   });
 
   describe('when a pattern has a *', function () {
-    var pattern = '/files/*.jpg';
-
     describe('and the path matches', function () {
       it('returns an object with the params', function () {
-        expect(Path.extractParams(pattern, '/files/my/photo.jpg')).toEqual({ splat: 'my/photo' });
+        expect(Path.extractParams('/files/*', '/files/my/photo.jpg')).toEqual({ splat: 'my/photo.jpg' });
+        expect(Path.extractParams('/files/*', '/files/my/photo.jpg.zip')).toEqual({ splat: 'my/photo.jpg.zip' });
+        expect(Path.extractParams('/files/*.jpg', '/files/my/photo.jpg')).toEqual({ splat: 'my/photo' });
       });
     });
 
     describe('and the path does not match', function () {
       it('returns null', function () {
-        expect(Path.extractParams(pattern, '/files/my/photo.png')).toBe(null);
+        expect(Path.extractParams('/files/*.jpg', '/files/my/photo.png')).toBe(null);
       });
     });
   });
-});
 
-describe('Path.extractParamNames', function () {
-  describe('when a pattern contains no dynamic segments', function () {
-    it('returns an empty array', function () {
-      expect(Path.extractParamNames('a/b/c')).toEqual([]);
-    });
-  });
+  describe('when a pattern has a ?', function () {
+    var pattern = '/archive/?:name?';
 
-  describe('when a pattern contains :a and :b dynamic segments', function () {
-    it('returns the correct names', function () {
-      expect(Path.extractParamNames('/comments/:a/:b/edit')).toEqual([ 'a', 'b' ]);
+    describe('and the path matches', function () {
+      it('returns an object with the params', function () {
+        expect(Path.extractParams(pattern, '/archive')).toEqual({ name: undefined });
+        expect(Path.extractParams(pattern, '/archive/')).toEqual({ name: undefined });
+        expect(Path.extractParams(pattern, '/archive/foo')).toEqual({ name: 'foo' });
+        expect(Path.extractParams(pattern, '/archivefoo')).toEqual({ name: 'foo' });
+      });
     });
-  });
 
-  describe('when a pattern has a *', function () {
-    it('uses the name "splat"', function () {
-      expect(Path.extractParamNames('/files/*.jpg')).toEqual([ 'splat' ]);
+    describe('and the path does not match', function () {
+      it('returns null', function () {
+        expect(Path.extractParams(pattern, '/archiv')).toBe(null);
+      });
     });
   });
 });
@@ -151,12 +170,22 @@ describe('Path.injectParams', function () {
       });
     });
   });
+
+  describe('when a pattern has multiple splats', function () {
+    it('returns the correct path', function () {
+      expect(Path.injectParams('/a/*/c/*', { splat: [ 'b', 'd' ] })).toEqual('/a/b/c/d');
+    });
+  });
 });
 
 describe('Path.extractQuery', function () {
   describe('when the path contains a query string', function () {
     it('returns the parsed query object', function () {
-      expect(Path.extractQuery('/a/b/c?id=def&show=true')).toEqual({ id: 'def', show: 'true' });
+      expect(Path.extractQuery('/?id=def&show=true')).toEqual({ id: 'def', show: 'true' });
+    });
+
+    it('properly handles arrays', function () {
+      expect(Path.extractQuery('/?id%5B%5D=a&id%5B%5D=b')).toEqual({ id: [ 'a', 'b' ] });
     });
   });
 
@@ -177,6 +206,10 @@ describe('Path.withQuery', function () {
   it('appends the query string', function () {
     expect(Path.withQuery('/a/b/c', { id: 'def' })).toEqual('/a/b/c?id=def');
   });
+
+  it('merges two query strings', function () {
+    expect(Path.withQuery('/path?a=b', { c: [ 'd', 'e' ]})).toEqual('/path?a=b&c%5B0%5D=d&c%5B1%5D=e');
+  });
 });
 
 describe('Path.normalize', function () {