diff --git a/AppKit/CPCompatibility.j b/AppKit/CPCompatibility.j
index 8dd1686d5f..8a0e3c0234 100644
--- a/AppKit/CPCompatibility.j
+++ b/AppKit/CPCompatibility.j
@@ -83,7 +83,8 @@ CPCanvasParentDrawErrorsOnMovementBug   = 1 << 0;
 var USER_AGENT                          = "",
     PLATFORM_ENGINE                     = CPUnknownBrowserEngine,
     PLATFORM_FEATURES                   = 0,
-    PLATFORM_BUGS                       = 0;
+    PLATFORM_BUGS                       = 0,
+    PLATFORM_STYLE_JS_PROPERTIES        = {};
 
 // default these features to true
 
@@ -273,3 +274,87 @@ else
     CPUndoKeyEquivalentModifierMask = CPControlKeyMask;
     CPRedoKeyEquivalentModifierMask = CPControlKeyMask;
 }
+
+/*!
+    Return the properly prefixed JS property for the given name. E.g. in a webkit browser,
+    CPBrowserStyleProperty('transition') -> WebkitTransition
+
+    While technically not a style property, style related event handler names are also supported.
+    CPBrowserStyleProperty('transitionend') -> 'webkitTransitionEnd'
+
+    CSS is only available in platform(dom), so don't rely too heavily on it.
+*/
+function CPBrowserStyleProperty(aProperty)
+{
+    var lowerProperty = aProperty.toLowerCase();
+
+    if (PLATFORM_STYLE_JS_PROPERTIES[lowerProperty] === undefined)
+    {
+        var r = nil;
+
+#if PLATFORM(DOM)
+        var testElement = document.createElement('div');
+
+        switch (lowerProperty)
+        {
+            case 'transitionend':
+                var candidates = {
+                        'WebkitTransition' : 'webkitTransitionEnd',
+                        'MozTransition'    : 'transitionend',
+                        'OTransition'      : 'oTransitionEnd',
+                        'msTransition'     : 'MSTransitionEnd',
+                        'transition'       : 'transitionend'
+                    };
+
+                r = candidates[PLATFORM_STYLE_JS_PROPERTIES['transition']] || nil;
+                break;
+            default:
+                var prefixes = ["Webkit", "Moz", "O", "ms"],
+                    capProperty = [aProperty capitalizedString];
+
+                for (var i = 0; i < prefixes.length; i++)
+                {
+                    if (prefixes[i] + capProperty in testElement.style)
+                    {
+                        r = prefixes[i] + capProperty;
+                        break;
+                    }
+                }
+
+                if (!r && lowerProperty in testElement.style)
+                    r = lowerProperty;
+
+                break;
+        }
+#endif
+
+        PLATFORM_STYLE_JS_PROPERTIES[lowerProperty] = r;
+    }
+
+    return PLATFORM_STYLE_JS_PROPERTIES[lowerProperty];
+}
+
+function CPBrowserCSSProperty(aProperty)
+{
+    var browserProperty = CPBrowserStyleProperty(aProperty);
+
+    if (!browserProperty)
+        return nil;
+
+    var prefixes = {
+            'Webkit': '-webkit-',
+            'Moz': '-moz-',
+            'O': '-o-',
+            'ms': '-ms-'
+        };
+
+    for (var prefix in prefixes)
+    {
+        if (browserProperty.substring(0, prefix.length) == prefix)
+        {
+            return prefixes[prefix] + browserProperty.substring(prefix.length).toLowerCase();
+        }
+    }
+
+    return browserProperty.toLowerCase();
+}
diff --git a/AppKit/_CPAttachedWindow.j b/AppKit/_CPAttachedWindow.j
index 2ac249dfa6..52c0d81f49 100644
--- a/AppKit/_CPAttachedWindow.j
+++ b/AppKit/_CPAttachedWindow.j
@@ -134,7 +134,7 @@ var _CPAttachedWindow_attachedWindowShouldClose_    = 1 << 0,
         [self setMovableByWindowBackground:YES];
         [self setHasShadow:NO];
 
-        [self setCSS3Property:@"TransitionProperty" value:@"-webkit-transform, opacity"];
+        [self setCSS3Property:@"TransitionProperty" value:CPBrowserCSSProperty('transform') + @", opacity"];
 
         [_windowView setNeedsDisplay:YES];
     }
@@ -350,25 +350,18 @@ var _CPAttachedWindow_attachedWindowShouldClose_    = 1 << 0,
 }
 
 /*! @ignore */
-- (void)setCSS3Property:(CPString)property value:(CPString)value
+- (void)setCSS3Property:(CPString)aProperty value:(CPString)value
 {
-    _DOMElement.style['webkit' + property] = value;
+    var browserProperty = CPBrowserStyleProperty(aProperty);
 
-    // Support other browsers here eventually
+    if (browserProperty)
+        _DOMElement.style[browserProperty] = value;
 }
 
 /*! @ignore */
 - (BOOL)browserSupportsAnimation
 {
-    return typeof(_DOMElement.style.webkitTransition) !== "undefined";
-
-    /*
-        No others browsers supported yet.
-
-           typeof(_DOMElement.style.MozTransition) !== "undefined" ||
-           typeof(_DOMElement.style.MsTransition) !== "undefined" ||
-           typeof(_DOMElement.style.OTransition) !== "undefined";
-    */
+    return CPBrowserStyleProperty('transition') && CPBrowserStyleProperty('transitionend');
 }
 
 #pragma mark -
@@ -452,28 +445,28 @@ var _CPAttachedWindow_attachedWindowShouldClose_    = 1 << 0,
 
                 // Set up the pop-out transition
                 [self setCSS3Property:@"Transform" value:@"scale(1.1)"];
-                [self setCSS3Property:@"Transition" value:@"-webkit-transform 200ms ease-in"];
+                [self setCSS3Property:@"Transition" value:CPBrowserCSSProperty('transform') + @" 200ms ease-in"];
 
                 var transitionEndFunction = function()
                 {
-                    _DOMElement.removeEventListener("webkitTransitionEnd", transitionEndFunction, YES);
+                    _DOMElement.removeEventListener(CPBrowserStyleProperty('transitionend'), transitionEndFunction, YES);
 
                     // Now set up the pop-in to normal size transition.
                     // Because we are watching the -webkit-transform, it will occur now.
                     [self setCSS3Property:@"Transform" value:@"scale(1)"];
-                    [self setCSS3Property:@"Transition" value:@"-webkit-transform 50ms linear"];
+                    [self setCSS3Property:@"Transition" value:CPBrowserCSSProperty('transform') + @" 50ms linear"];
 
                     var transitionCompleteFunction = function()
                     {
-                        _DOMElement.removeEventListener("webkitTransitionEnd", transitionCompleteFunction, YES);
+                        _DOMElement.removeEventListener(CPBrowserStyleProperty('transitionend'), transitionCompleteFunction, YES);
                         if (_implementedDelegateMethods & _CPAttachedWindow_attachedWindowDidShow_)
                              [_delegate attachedWindowDidShow:self];
                     }
 
-                    _DOMElement.addEventListener("webkitTransitionEnd", transitionCompleteFunction, YES);
+                    _DOMElement.addEventListener(CPBrowserStyleProperty('transitionend'), transitionCompleteFunction, YES);
                 };
 
-                _DOMElement.addEventListener("webkitTransitionEnd", transitionEndFunction, YES);
+                _DOMElement.addEventListener(CPBrowserStyleProperty('transitionend'), transitionEndFunction, YES);
             }, 0);
         }
         else
@@ -506,11 +499,11 @@ var _CPAttachedWindow_attachedWindowShouldClose_    = 1 << 0,
 
         var transitionEndFunction = function()
         {
-            _DOMElement.removeEventListener("webkitTransitionEnd", transitionEndFunction, YES);
+            _DOMElement.removeEventListener(CPBrowserStyleProperty("transitionend"), transitionEndFunction, YES);
             [self _close];
         };
 
-        _DOMElement.addEventListener("webkitTransitionEnd", transitionEndFunction, YES);
+        _DOMElement.addEventListener(CPBrowserStyleProperty("transitionend"), transitionEndFunction, YES);
     }
     else
     {