diff --git a/CHANGELOG b/CHANGELOG
index 95c1d93..859852d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Add support for JSON encoding and decoding.  Closes #7427.  [Tobie Langel]
+
 * Fix double escaping of query parameters in Hash.prototype.toQueryString, and prevent Safari from iterating over shadowed properties when creating hashes.  Closes #7421.  [Tobie Langel, Mislav Marohnić]
 
 * Fix simulated attribute reading for IE for "href", "src" and boolean attributes.  [Mislav Marohnić, Thomas Fuchs]
diff --git a/src/array.js b/src/array.js
index 9271f6a..fd0a427 100644
--- a/src/array.js
+++ b/src/array.js
@@ -86,6 +86,15 @@ Object.extend(Array.prototype, {
   
   inspect: function() {
     return '[' + this.map(Object.inspect).join(', ') + ']';
+  },
+  
+  toJSON: function() {
+    var results = [];
+    this.each(function(object) {
+      var value = Object.toJSON(object);
+      if (value !== undefined) results.push(value);
+    });
+    return '[' + results.join(',') + ']';
   }
 });
 
diff --git a/src/base.js b/src/base.js
index cf2f438..d0d7535 100644
--- a/src/base.js
+++ b/src/base.js
@@ -27,6 +27,26 @@ Object.extend(Object, {
     }
   },
   
+  toJSON: function(object) {
+    var type = typeof object;
+    switch(type) {
+      case 'undefined':
+      case 'function':
+      case 'unknown': return;
+      case 'boolean': return object.toString();
+    }
+    if (object === null) return 'null';
+    if (object.toJSON) return object.toJSON();
+    if (object.ownerDocument === document) return;
+    var results = [];
+    for (var property in object) {
+      var value = Object.toJSON(object[property]);
+      if (value !== undefined)
+        results.push(property.toJSON() + ':' + value);
+    }
+    return '{' + results.join(',') + '}';
+  },
+  
   keys: function(object) {
     var keys = [];
     for (var property in object)
@@ -62,9 +82,7 @@ Function.prototype.bindAsEventListener = function(object) {
 
 Object.extend(Number.prototype, {
   toColorPart: function() {
-    var digits = this.toString(16);
-    if (this < 16) return '0' + digits;
-    return digits;
+    return this.toPaddedString(2, 16);
   },
 
   succ: function() {
@@ -74,9 +92,27 @@ Object.extend(Number.prototype, {
   times: function(iterator) {
     $R(0, this, true).each(iterator);
     return this;
+  },
+  
+  toPaddedString: function(length, radix) {
+    var string = this.toString(radix || 10);
+    return '0'.times(length - string.length) + string;
+  },
+  
+  toJSON: function(){
+    return isFinite(this) ? this.toString() : 'null';
   }
 });
 
+Date.prototype.toJSON = function() {
+  return '"' + this.getFullYear() + '-' +
+    (this.getMonth() + 1).toPaddedString(2) + '-' +
+    this.getDate().toPaddedString(2) + 'T' +
+    this.getHours().toPaddedString(2) + ':' +
+    this.getMinutes().toPaddedString(2) + ':' +
+    this.getSeconds().toPaddedString(2) + '"';
+};
+
 var Try = {
   these: function() {
     var returnValue;
diff --git a/src/hash.js b/src/hash.js
index 642d6bc..efeb3d1 100644
--- a/src/hash.js
+++ b/src/hash.js
@@ -22,6 +22,15 @@ Object.extend(Hash, {
     });
     
     return parts.join('&');
+  },
+  
+  toJSON: function(object) {
+    var results = [];
+    this.prototype._each.call(object, function(pair){
+      var value = Object.toJSON(pair.value);
+      if (value !== undefined) results.push(pair.key.toJSON() + ':' + value);
+    });
+    return '{' + results.join(',') + '}';
   }
 });
 
@@ -84,6 +93,10 @@ Object.extend(Hash.prototype, {
     return '#<Hash:{' + this.map(function(pair) {
       return pair.map(Object.inspect).join(': ');
     }).join(', ') + '}>';
+  },
+  
+  toJSON: function() {
+    return Hash.toJSON(this);
   }
 });
 
diff --git a/src/string.js b/src/string.js
index 5a575e0..c81e45a 100644
--- a/src/string.js
+++ b/src/string.js
@@ -1,6 +1,16 @@
-String.interpret = function(value) {
-  return value == null ? '' : String(value);
-}
+Object.extend(String, {
+  interpret: function(value){
+    return value == null ? '' : String(value);
+  },
+  specialChar: {
+    '\b': '\\b',
+    '\t': '\\t',
+    '\n': '\\n',
+    '\f': '\\f',
+    '\r': '\\r',
+    '\\': '\\\\'
+  }
+});
 
 Object.extend(String.prototype, {
   gsub: function(pattern, replacement) {
@@ -107,7 +117,13 @@ Object.extend(String.prototype, {
     return this.slice(0, this.length - 1) +
       String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
   },
-
+  
+  times: function(count) {
+    var result = '';
+    for (var i = 0; i < count; i++) result += this;
+    return result;
+  },
+  
   camelize: function() {
     var parts = this.split('-'), len = parts.length;
     if (len == 1) return parts[0];
@@ -135,13 +151,26 @@ Object.extend(String.prototype, {
   },
 
   inspect: function(useDoubleQuotes) {
-    var escapedString = this.replace(/\\/g, '\\\\');
-    if (useDoubleQuotes)
-      return '"' + escapedString.replace(/"/g, '\\"') + '"';
-    else
-      return "'" + escapedString.replace(/'/g, '\\\'') + "'";
+    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
+      var character = String.specialChar[match[0]];
+      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
+    });
+    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
+    return "'" + escapedString.replace(/'/g, '\\\'') + "'";
+  },
+  
+  toJSON: function(){
+    return this.inspect(true);
   },
 
+  evalJSON: function(sanitize){
+    try {
+      if (!sanitize || (/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/.test(this)))
+        return eval('(' + this + ')');
+    } catch(e) {}
+    throw new SyntaxError('Badly formated JSON string: ' + this.inspect());
+  },
+  
   include: function(pattern) {
     return this.indexOf(pattern) > -1;
   },
diff --git a/test/unit/array.html b/test/unit/array.html
index f8518ff..171c9d2 100644
--- a/test/unit/array.html
+++ b/test/unit/array.html
@@ -102,6 +102,13 @@
       assertEqual('[\'a\', 1]',['a',1].inspect());
     }},
     
+    testToJSON: function(){ with(this) {
+      assertEqual('[]', Object.toJSON([]));
+      assertEqual('[\"a\"]', Object.toJSON(['a']));
+      assertEqual('[\"a\",1]', Object.toJSON(['a', 1]));
+      assertEqual('[\"a\",{\"b\":null}]', Object.toJSON(['a', {'b': null}]));
+    }},
+        
     testReduce: function(){ with(this) {
       assertUndefined([].reduce());
       assertNull([null].reduce());
diff --git a/test/unit/base.html b/test/unit/base.html
index c5e7ddf..4dc1cf8 100644
--- a/test/unit/base.html
+++ b/test/unit/base.html
@@ -22,11 +22,17 @@
 
 <!-- Log output -->
 <div id="testlog"> </div>
-
+<div id="test"></div> 
 <!-- Tests follow -->
 <script type="text/javascript" language="javascript" charset="utf-8">
 // <![CDATA[
-
+  var Person = function(name){
+      this.name = name;
+  };
+  
+  Person.prototype.toJSON = function() {
+    return '-' + this.name;
+  };
 
   var peEventCount = 0;
   // peEventFired will stop the PeriodicalExecuter after 3 callbacks
@@ -87,6 +93,33 @@
       assertEqual('[]', Object.inspect([]));
     }},
     
+    testObjectToJSON: function() { with(this) {
+      assertUndefined(Object.toJSON(undefined));
+      assertUndefined(Object.toJSON(Prototype.K));
+      assertEqual('\"\"', Object.toJSON(''));
+      assertEqual('[]', Object.toJSON([]));
+      assertEqual('[\"a\"]', Object.toJSON(['a']));
+      assertEqual('[\"a\",1]', Object.toJSON(['a', 1]));
+      assertEqual('[\"a\",{\"b\":null}]', Object.toJSON(['a', {'b': null}]));
+      assertEqual('{\"a\":\"hello!\"}', Object.toJSON({a: 'hello!'}));
+      assertEqual('{}', Object.toJSON({}));
+      assertEqual('{}', Object.toJSON({a: undefined, b: undefined, c: Prototype.K}));
+      assertEqual('{\"b\":[false,true],\"c\":{\"a\":\"hello!\"}}',
+        Object.toJSON({'b': [undefined, false, true, undefined], c: {a: 'hello!'}}));
+      assertEqual('{\"b\":[false,true],\"c\":{\"a\":\"hello!\"}}',
+        Object.toJSON($H({'b': [undefined, false, true, undefined], c: {a: 'hello!'}})));
+      assertEqual('true', Object.toJSON(true));
+      assertEqual('false', Object.toJSON(false));
+      assertEqual('null', Object.toJSON(null));
+      var sam = new Person('sam');
+      assertEqual('-sam', Object.toJSON(sam));
+      assertEqual('-sam', sam.toJSON());
+      var element = $('test');
+      assertUndefined(Object.toJSON(element));
+      element.toJSON = function(){return 'I\'m a div with id test'};
+      assertEqual('I\'m a div with id test', Object.toJSON(element));
+    }},
+    
     // sanity check
     testDoesntExtendObjectPrototype: function() {with(this) {
       // for-in is supported with objects
@@ -125,6 +158,32 @@
       }
     },
     
+    testNumberToColorPart: function() {with(this) {
+      assertEqual('00', (0).toColorPart());
+      assertEqual('0a', (10).toColorPart());
+      assertEqual('ff', (255).toColorPart());
+    }},
+    
+    testNumberToPaddedString: function() {with(this) {
+      assertEqual('00', (0).toPaddedString(2, 16));
+      assertEqual('0a', (10).toPaddedString(2, 16));
+      assertEqual('ff', (255).toPaddedString(2, 16));
+      assertEqual('000', (0).toPaddedString(3));
+      assertEqual('010', (10).toPaddedString(3));
+      assertEqual('100', (100).toPaddedString(3));
+      assertEqual('1000', (1000).toPaddedString(3));
+    }},
+    
+    testNumberToJSON: function() {with(this) {
+      assertEqual('null', Number.NaN.toJSON());
+      assertEqual('0', (0).toJSON());
+      assertEqual('-293', (-293).toJSON());
+    }},
+    
+    testDateToJSON: function() {with(this) {
+      assertEqual('\"1969-12-31T19:00:00\"', new Date(1969, 11, 31, 19).toJSON());
+    }},
+    
     testBrowserDetection: function() {with(this) {
       var results = $H(Prototype.Browser).map(function(engine){
         return engine;
diff --git a/test/unit/hash.html b/test/unit/hash.html
index 5e399be..1671632 100644
--- a/test/unit/hash.html
+++ b/test/unit/hash.html
@@ -126,6 +126,13 @@
       assertEqual('#<Hash:{}>',              $H({}).inspect());
       assertEqual("#<Hash:{'a': 'A#'}>",     $H(Fixtures.one).inspect());
       assertEqual("#<Hash:{'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D#'}>", $H(Fixtures.many).inspect());
+    }},
+    
+    testToJSON: function(){ with(this) {
+      assertEqual('{\"b\":[false,true],\"c\":{\"a\":\"hello!\"}}',
+        $H({'b': [undefined, false, true, undefined], c: {a: 'hello!'}}).toJSON());
+
+      assertEqual('E', eval('(' + $H(Fixtures.dangerous).toJSON() + ')')._each);
     }}
   }, 'testlog');
 // ]]>
diff --git a/test/unit/string.html b/test/unit/string.html
index 1200890..a92e55a 100644
--- a/test/unit/string.html
+++ b/test/unit/string.html
@@ -26,6 +26,7 @@
 <!-- Tests follow -->
 <script type="text/javascript" language="javascript" charset="utf-8">
 // <![CDATA[
+  var attackTarget;
   var evalScriptsCounter = 0,
       largeTextEscaped = '&lt;span&gt;test&lt;/span&gt;', 
       largeTextUnescaped = '<span>test</span>';
@@ -320,6 +321,11 @@
       assertEqual('\'\'', ''.inspect());
       assertEqual('\'test\'', 'test'.inspect());
       assertEqual('\'test \\\'test\\\' "test"\'', 'test \'test\' "test"'.inspect());
+      assertEqual('\"test \'test\' \\"test\\"\"', 'test \'test\' "test"'.inspect(true));
+      assertEqual('\'\\b\\t\\n\\f\\r"\\\\\'', '\b\t\n\f\r"\\'.inspect());
+      assertEqual('\"\\b\\t\\n\\f\\r\\"\\\\\"', '\b\t\n\f\r"\\'.inspect(true));
+      assertEqual('\'\\b\\t\\n\\f\\r\'', '\x08\x09\x0a\x0c\x0d'.inspect());
+      assertEqual('\'\\u001a\'', '\x1a'.inspect());
     }},
     
     testInclude: function() {with(this) {
@@ -369,7 +375,41 @@
       assertEqual('abce', 'abcd'.succ());
       assertEqual('{', 'z'.succ());
       assertEqual(':', '9'.succ());
-    }}
+    }},
+
+    testTimes: function() {with(this) {
+      assertEqual('', ''.times(0));
+      assertEqual('', ''.times(5));
+      assertEqual('', 'a'.times(0));
+      assertEqual('a', 'a'.times(1));
+      assertEqual('aaaaa', 'a'.times(5));
+      assertEqual('foofoofoofoofoo', 'foo'.times(5));
+      assertEqual('', 'foo'.times(-5));
+    }},
+    
+    testToJSON: function() {with(this) {
+      assertEqual('\"\"', ''.toJSON());
+      assertEqual('\"test\"', 'test'.toJSON());
+    }},
+
+    testEvalJSON: function() {with(this) {
+      var valid = '{test: "hello world!"}';
+      var invalid = '{test: "hello world!"';
+      var dangerous = '{});attackTarget = "attack succeeded!";({}';
+      
+      assertEqual('hello world!', valid.evalJSON().test);
+      assertEqual('hello world!', valid.evalJSON(true).test);
+      assertRaise('SyntaxError', function(){invalid.evalJSON();});
+      assertRaise('SyntaxError', function(){invalid.evalJSON(true);});
+
+      attackTarget = "scared";      
+      dangerous.evalJSON();
+      assertEqual("attack succeeded!", attackTarget);
+      
+      attackTarget = "Not scared!";
+      assertRaise('SyntaxError', function(){dangerous.evalJSON(true)});
+      assertEqual("Not scared!", attackTarget);
+     }}
   }, 'testlog');
 // ]]>
 </script>