diff --git a/AppKit/CPTreeNode.j b/AppKit/CPTreeNode.j
index 8d679da20..8c59f85b5 100644
--- a/AppKit/CPTreeNode.j
+++ b/AppKit/CPTreeNode.j
@@ -87,6 +87,40 @@
         [_childNodes[count] sortWithSortDescriptors:sortDescriptors recursively:YES];
 }
 
+- (CPEnumerator)preOrder
+{
+    return [_CPTreeNodeEnumerator enumeratorWithTreeNode:self order:_CPTreeNodeEnumeratorPreOrder];
+}
+
+- (CPEnumerator)inOrder
+{
+    return [_CPTreeNodeEnumerator enumeratorWithTreeNode:self order:_CPTreeNodeEnumeratorInOrder];
+}
+
+- (CPEnumerator)postOrder
+{
+    return [_CPTreeNodeEnumerator enumeratorWithTreeNode:self order:_CPTreeNodeEnumeratorPostOrder];
+}
+
+- (CPEnumerator)levelOrder
+{
+    return [_CPTreeNodeEnumerator enumeratorWithTreeNode:self order:_CPTreeNodeEnumeratorLevelOrder];
+}
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    if (aState.state !== 0)
+        return 0;
+
+    // FIXME: Change this to inorder when implemented?
+    var count = [[self preOrder] countByEnumeratingWithState:aState objects:objects count:aCount];
+
+    // Dangerous?
+    aState.state = YES;
+
+    return count;
+}
+
 @end
 
 var CPTreeNodeRepresentedObjectKey  = @"CPTreeNodeRepresentedObjectKey",
@@ -117,3 +151,166 @@ var CPTreeNodeRepresentedObjectKey  = @"CPTreeNodeRepresentedObjectKey",
 }
 
 @end
+
+var _CPTreeNodeEnumeratorPreOrder   = 0,
+    _CPTreeNodeEnumeratorInOrder    = 1,
+    _CPTreeNodeEnumeratorPostOrder  = 2,
+    _CPTreeNodeEnumeratorLevelOrder = 3;
+
+@implementation _CPTreeNodeEnumerator : CPEnumerator
+{
+    int         _order;
+    Object      _state;
+    CPTreeNode  _treeNode;
+}
+
++ (_CPTreeNodeEnumerator)enumeratorWithTreeNode:(CPTreeNode)aTreeNode order:(int)anOrder
+{
+    return [[self alloc] initWithTreeNode:aTreeNode order:anOrder];
+}
+
+- (id)initWithTreeNode:(CPTreeNode)aTreeNode order:(int)anOrder
+{
+    self = [super init];
+
+    if (self)
+    {
+        _order = anOrder
+        _state = [self _newState];
+        _treeNode = aTreeNode;
+    }
+
+    return self;
+}
+
+- (id)_newState
+{
+    return { stack:[_treeNode], visited:[CPSet set] };
+}
+
+- (id)_preOrderFromState:(Object)state allObjects:(BOOL)shouldReturnAllObjects
+{
+    var stack = state.stack;
+
+    if (stack.length <= 0)
+        return nil;
+
+    if (shouldReturnAllObjects)
+        var allObjects = [];
+
+    while (stack.length)
+    {
+        var currentNode = stack.pop(),
+            childNodes = currentNode._childNodes,
+            count = childNodes.length;
+
+        while (count--)
+            stack.push(childNodes[count]);
+
+        if (shouldReturnAllObjects)
+            allObjects.push(currentNode);
+        else
+            return currentNode;
+    }
+
+    return allObjects;
+}
+
+- (id)_inOrderFromState:(Object)state allObjects:(BOOL)shouldReturnAllObjects
+{
+    // Implement.
+}
+
+- (id)_postOrderFromState:(Object)state allObjects:(BOOL)shouldReturnAllObjects
+{
+    var stack = state.stack;
+
+    if (stack.length <= 0)
+        return nil;
+
+    var visited = state.visited;
+
+    if (shouldReturnAllObjects)
+        var allObjects = [];
+
+    while (stack.length)
+    {
+        var currentNode = [stack lastObject],
+            childNodes = currentNode._childNodes,
+            originalCount = stack.length,
+            count = childNodes.length;
+
+        while (count--)
+        {
+            var treeNode = childNodes[count];
+
+            if ([visited containsObject:treeNode])
+                continue;
+            else
+                stack.push(treeNode);
+        }
+
+        if (originalCount === stack.length)
+        {
+            [visited addObject:currentNode];
+
+            if (shouldReturnAllObjects)
+                allObjects.push(stack.pop());
+            else
+                return stack.pop();
+        }
+    }
+
+    return allObjects;
+}
+
+- (id)_levelOrderFromState:(Object)state allObjects:(BOOL)shouldReturnAllObjects
+{
+    // Implement.
+}
+
+- (id)nextObject
+{
+    if (_order === _CPTreeNodeEnumeratorPreOrder)
+        return [self _preOrderFromState:[self _newState] allObjects:NO];
+
+    else if (_order === _CPTreeNodeEnumeratorInOrder)
+        return [self _inOrderFromState:[self _newState] allObjects:NO];
+
+    else if (_order === _CPTreeNodeEnumeratorPostOrder)
+        return [self _postOrderFromState:[self _newState] allObjects:NO];
+
+    //else if (_order === _CPTreeNodeEnumeratorLevelOrder)
+        return [self _levelOrderFromState:[self _newState] allObjects:NO];
+
+}
+
+- (CPArray)allObjects
+{
+    if (_order === _CPTreeNodeEnumeratorPreOrder)
+        return [self _preOrderFromState:[self _newState] allObjects:YES];
+
+    else if (_order === _CPTreeNodeEnumeratorInOrder)
+        return [self _inOrderFromState:[self _newState] allObjects:YES];
+
+    else if (_order === _CPTreeNodeEnumeratorPostOrder)
+        return [self _postOrderFromState:[self _newState] allObjects:YES];
+
+    //else if (_order === _CPTreeNodeEnumeratorLevelOrder)
+        return [self _levelOrderFromState:[self _newState] allObjects:NO];
+}
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    if (aState.state !== 0)
+        return 0;
+
+    var count = [[self allObjects] countByEnumeratingWithState:aState objects:objects count:aCount];
+
+    // Dangerous?
+    aState.state = YES;
+
+    return count;
+}
+
+@end
diff --git a/Foundation/CPArray.j b/Foundation/CPArray.j
index eeb8bad8b..ec071fe46 100755
--- a/Foundation/CPArray.j
+++ b/Foundation/CPArray.j
@@ -55,6 +55,11 @@
     return [_array objectAtIndex:_index];
 }
 
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    return [_array countByEnumeratingWithState:aState objects:objects count:aCount];
+}
+
 @end
 
 /* @ignore */
@@ -1206,6 +1211,31 @@
 
 @end
 
+@implementation CPArray (CPFastEnumeration)
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    var count = [self count],
+        index = aState.state;
+
+    if (index >= count)
+        return 0;
+
+    var indexIndex = 0,
+        last = MIN(index + aCount, count);
+
+    aCount = last - index;
+
+    for (; index < last; ++index, ++indexIndex)
+        objects[indexIndex] = [self objectAtIndex:index];
+
+    aState.state = last;
+
+    return aCount;
+}
+
+@end
+
 @implementation CPArray (CPCoding)
 
 - (id)initWithCoder:(CPCoder)aCoder
diff --git a/Foundation/CPDictionary.j b/Foundation/CPDictionary.j
index e6f83f56a..d4646bf43 100755
--- a/Foundation/CPDictionary.j
+++ b/Foundation/CPDictionary.j
@@ -546,6 +546,31 @@
 
 @end
 
+@implementation CPDictionary (CPFastEnumeration)
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    var count = [self count];
+
+    if (aState.state >= count)
+        return 0;
+
+    var keys = [self allKeys],
+        index = count,
+        objects = new Array(count);
+
+    while (index--)
+        objects[index] = [self objectForKey:keys[index]];
+
+    aState.items0 = objects;
+    aState.items1 = keys;
+    aState.state = count;
+
+    return count;
+}
+
+@end
+
 /*!
     @class CPMutableDictionary
     @ingroup compatability
diff --git a/Foundation/CPEnumerator.j b/Foundation/CPEnumerator.j
index 51d25b92a..21084487f 100755
--- a/Foundation/CPEnumerator.j
+++ b/Foundation/CPEnumerator.j
@@ -56,4 +56,11 @@
     return [];
 }
 
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    // This is pretty terrible, but what do you expect.
+    return [[self allObjects] countByEnumeratingWithState:aState objects:objects count:aCount];
+}
+
 @end
diff --git a/Foundation/CPIndexSet.j b/Foundation/CPIndexSet.j
index 03b427d34..03e3a2d82 100644
--- a/Foundation/CPIndexSet.j
+++ b/Foundation/CPIndexSet.j
@@ -834,6 +834,32 @@ var CPIndexSetCountKey              = @"CPIndexSetCountKey",
 
 @end
 
+@implementation CPIndexSet (CPFastEnumeration)
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    var rangeIndex = aState.state;
+
+    if (aState.state >= _ranges.length)
+        return 0;
+
+    var range = _ranges[rangeIndex],
+        index = 0,
+        start = range.location,
+        end = start + range.length,
+        indexes = new Array(range.length);
+
+    while (start < end)
+        indexes[index++] = start++;
+
+    aState.items = indexes;
+    ++aState.state;
+
+    return range.length;
+}
+
+@end
+
 /*!
     @class CPMutableIndexSet
     @ingroup compatability
diff --git a/Foundation/CPNull.j b/Foundation/CPNull.j
index 43ba1cbc9..cd67e9e1e 100644
--- a/Foundation/CPNull.j
+++ b/Foundation/CPNull.j
@@ -58,3 +58,12 @@ var CPNullSharedNull = nil;
 }
 
 @end
+
+@implementation CPNull (CPFastEnumeration)
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    return 0;
+}
+
+@end
diff --git a/Foundation/CPSet.j b/Foundation/CPSet.j
index 7026a376e..fd28da504 100644
--- a/Foundation/CPSet.j
+++ b/Foundation/CPSet.j
@@ -499,6 +499,22 @@ var CPSetObjectsKey = @"CPSetObjectsKey";
 
 @end
 
+@implementation CPSet (CPFastEnumeration)
+
+- (int)countByEnumeratingWithState:(id)aState objects:(id)objects count:(id)aCount
+{
+    var count = [self count];
+
+    if (aState.state >= count)
+        return 0;
+
+    count = [[self allObjects] countByEnumeratingWithState:aState objects:objects count:aCount];
+
+    return count;
+}
+
+@end
+
 /*!
     @class CPMutableSet
     @ingroup compatability
diff --git a/Objective-J/Preprocessor.js b/Objective-J/Preprocessor.js
index fec6b2758..edc0924f5 100644
--- a/Objective-J/Preprocessor.js
+++ b/Objective-J/Preprocessor.js
@@ -321,6 +321,9 @@ Preprocessor.prototype.directive = function(tokens, aStringBuffer, allowedDirect
     else if (token === TOKEN_IMPORT)
         this._import(tokens);
 
+    else if (token === TOKEN_EACH)
+        this.each(tokens, buffer);
+
     // @selector
     else if (token === TOKEN_SELECTOR)
         this.selector(tokens, buffer);
@@ -329,6 +332,99 @@ Preprocessor.prototype.directive = function(tokens, aStringBuffer, allowedDirect
         return buffer;
 }
 
+var fastEnumeratorCount = 0;
+
+Preprocessor.prototype.each = function(tokens, /*StringBuffer*/ aStringBuffer)
+{
+    var token = tokens.skip_whitespace();
+
+    // If we reach an open parenthesis, we are declaring a category.
+    if (token !== TOKEN_OPEN_PARENTHESIS)
+       throw new SyntaxError(this.error_message("*** Expecting (, found: \"" + token + "\"."));
+
+    var identifiers = [],
+        isVared = NO;
+
+    do
+    {
+        token = tokens.skip_whitespace();
+
+        if (identifiers.length === 0 && token === TOKEN_VAR)
+        {
+            isVared = YES;
+
+            token = tokens.skip_whitespace();
+        }
+
+        if (!TOKEN_IDENTIFIER.test(token))
+            throw new SyntaxError(this.error_message("*** Expecting identifier, found: \"" + token + "\"."));
+
+        identifiers.push(token);
+
+        token = tokens.skip_whitespace();
+
+        if (token !== TOKEN_COMMA && token !== TOKEN_IN)
+            throw new SyntaxError(this.error_message("*** Expecting \",\", found: \"" + token + "\"."));
+
+    } while (token && token === TOKEN_COMMA);
+
+    if (token !== TOKEN_IN)
+        throw new SyntaxError(this.error_message("*** Expecting \"in\", found: \"" + token + "\"."));
+
+    var generatedFastEnumeratorName = "$OBJJ_GENERATED_FAST_ENUMERATOR_" + fastEnumeratorCount++;
+
+    CONCAT(aStringBuffer, "var ");
+    CONCAT(aStringBuffer, generatedFastEnumeratorName);
+    CONCAT(aStringBuffer, " = new objj_fastEnumerator(");
+
+    this.preprocess(tokens, aStringBuffer, TOKEN_CLOSE_PARENTHESIS, TOKEN_OPEN_PARENTHESIS);
+
+    CONCAT(aStringBuffer, ", ");
+    CONCAT(aStringBuffer, identifiers.length);
+    CONCAT(aStringBuffer, ");\n");
+
+    // var $E = new objj_fastEnumerator(expression);
+    // for ([[var] arg1[, arg2[, ... argN]]];
+    // $E.i < $E.l || $E.e() && ((arg1 = $E.o0[$E.i][, $E.o1[$E.i][, ... $E.oN[$E.i]]]) || YES);
+    // ++$E.i)
+
+    CONCAT(aStringBuffer, "for (");
+
+    if (isVared)
+    {
+        CONCAT(aStringBuffer, "var ");
+        CONCAT(aStringBuffer, identifiers.join(", "));
+    }
+
+    CONCAT(aStringBuffer, ";(");
+    CONCAT(aStringBuffer, generatedFastEnumeratorName);
+    CONCAT(aStringBuffer, ".i < ");
+    CONCAT(aStringBuffer, generatedFastEnumeratorName);
+    CONCAT(aStringBuffer, ".l || ");
+    CONCAT(aStringBuffer, generatedFastEnumeratorName);
+    CONCAT(aStringBuffer, ".e()) && ((");
+
+    // Man don't you wish we had fast enumeration here!!
+    for (var index = 0, count = identifiers.length; index < count; ++index)
+    {
+        CONCAT(aStringBuffer, identifiers[index]);
+        CONCAT(aStringBuffer, " = ");
+        CONCAT(aStringBuffer, generatedFastEnumeratorName);
+        CONCAT(aStringBuffer, ".o");
+        CONCAT(aStringBuffer, index);
+        CONCAT(aStringBuffer, "[");
+        CONCAT(aStringBuffer, generatedFastEnumeratorName);
+        CONCAT(aStringBuffer, ".i]");
+
+        if (index + 1 < count)
+            CONCAT(aStringBuffer, ", ");
+    }
+
+    CONCAT(aStringBuffer, ") || YES); ++");
+    CONCAT(aStringBuffer, generatedFastEnumeratorName);
+    CONCAT(aStringBuffer, ".i)");
+}
+
 Preprocessor.prototype.implementation = function(tokens, /*StringBuffer*/ aStringBuffer)
 {
     var buffer = aStringBuffer,
diff --git a/Objective-J/Runtime.js b/Objective-J/Runtime.js
index f3ed81b90..3dd51bc20 100644
--- a/Objective-J/Runtime.js
+++ b/Objective-J/Runtime.js
@@ -530,3 +530,106 @@ GLOBAL(sel_registerName) = function(/*String*/ aName)
 {
     return aName;
 }
+
+var fastEnumerationSelector = sel_getUid("countByEnumeratingWithState:objects:count:");
+
+GLOBAL(objj_fastEnumerator) = function(/*Object*/ anObject, /*Integer*/ anAssigneeCount)
+{
+    // If this object doesn't respond to countByEnumeratingWithState:objects:count:
+    // (which is obviously the case for non-Objective-J objects), then just iterate
+    // this one object.
+    if (anObject && (!anObject.isa || !class_getInstanceMethod(anObject.isa, fastEnumerationSelector)))
+        this._target = [anObject];
+
+    // Else, use it's implementation.
+    else
+        this._target = anObject;
+
+    this._state = { state:0, assigneeCount:anAssigneeCount };
+    this._index = 0;
+
+    // Nothing to iterate in this case.
+    if (!anObject)
+    {
+        this.i = 0;
+        this.l = 0;
+    }
+    else
+        this.e();
+}
+
+objj_fastEnumerator.prototype.e = function()
+{
+    var object = this._target;
+
+    // Nothing to iterate, don't iterate
+    if (!object)
+        return NO;
+
+    var state = this._state,
+        index = state.assigneeCount;
+
+    while (index--)
+        state["items" + index] = nil;
+
+    this.i = 0;
+
+    // We optimize the array case.
+    if (CPArray && object.isa === CPArray)
+    {
+        if (this.l)
+            return NO;
+
+        this.o0 = object;
+        this.l = object.length;
+    }
+
+    else
+    {
+        // Clear out all the old state.
+        state.items = nil;
+        state.itemsPtr = nil;
+
+        this.o0 = [];
+        this.l = objj_msgSend(object, fastEnumerationSelector, state, this.o0, 16);
+
+        // We're flexible on this.
+        this.o0 = state.items || state.itemsPtr || state.items0 || this.o0;
+
+        // We allow the user to not explictly return anything in countByEnumeratingWithState:objects:count:
+        if (this.l === undefined)
+            this.l = this.o0.length;
+    }
+
+    var assigneeCount = state.assigneeCount;
+
+    index = assigneeCount - 1;
+
+    // Handle all items from [1 .. assigneeCount - 1]
+    while (index-- > 1)
+        this["o" + index] = state["items" + index] || [];
+
+    var lastAssigneeIndex = assigneeCount - 1;
+
+    // Autogenerate the indexes if this was left blank.
+    if (lastAssigneeIndex > 0)
+
+        if (state["items" + lastAssigneeIndex])
+            this["o" + lastAssigneeIndex] = state["items" + lastAssigneeIndex];
+
+        else
+        {
+            var count = this.l,
+                indexIndex = 0,
+                indexes = new Array(count)
+
+            for (; indexIndex < count; ++indexIndex, ++this._index)
+                indexes[indexIndex] = this._index;
+
+            this["o" + lastAssigneeIndex] = indexes;
+        }
+
+    // If this is the last iteration, set target to nil so that we don't call the
+    // fast enumeration method again.
+    return this.l > 0;
+}