diff --git a/Promise.js b/Promise.js
index 4ce46e9..e8dad6e 100644
--- a/Promise.js
+++ b/Promise.js
@@ -795,60 +795,53 @@ object.Constructor('ProxyPromise', Promise, {
 
 //---------------------------------------------------------------------
 
+// XXX EXPEREMENTAL...
+// XXX DOCS...
 // XXX like promise but if a value can be generated sync then this will 
 // 		run in sync otherwise it will fall back to being a promise...
-// 		...not sure where to return the sync value...
 // XXX potential problem is recursion (depth) on the sync stage...
-// XXX not sure if we need this..
-var MaybePromice =
-module.MaybePromice =
+// XXX should we throw errors in sync mode???
+var MaybePromise =
+module.MaybePromise =
 object.Constructor('MaybePromise', Promise, {
-	// XXX can we get into this without either .__error or .__result ???
+	//error: undefined,
+	//value: undefined,
+
 	then: function(resolve, reject){
-		if(this.hasOwnProperty('__error')){
+		if(this.hasOwnProperty('error')){
 			return this.constructor.reject(
 				reject ?
-					reject(this.__error)
-					: this.__error) }
-		if(this.hasOwnProperty('__result')){
+					reject(this.error)
+					: this.error) }
+		if(this.hasOwnProperty('value')){
 			return this.constructor.resolve(
-				resolve(this.__result)) } },
-	//catch: function(func){
-	//},
-	//finally: function(func){
-	//},
+				resolve(this.value)) } },
 
-	//__error: undefined,
-	//__result: undefined,
 	__new__: function(context, func){
 		var result
 		var resolve = function(res){
 			result = res }
+		var rejected
 		var error
 		var reject = function(err){
+			rejected = true
 			error = err }
-
+		// call...
 		try{
 			func(resolve, reject)
 		}catch(err){
 			reject(err) }
-
-		if(error){
-			this.__error = error
-
 		// async...
-		} else if(result instanceof Promise){
+		if(!error 
+				&& result instanceof Promise){
 			return result }
-
 		// sync...
-		this.__result = result
-		// XXX
-		var obj = Reflect.construct(
-			MaybePromise.__proto__,
-			[],
-			MaybePromise)
-		return obj
-	},
+		var obj = Promise.resolve(result)
+		obj.__proto__ = this.prototype
+		obj.value = result
+		rejected
+			&& (obj.error = error)
+		return obj },
 })
 
 
@@ -860,8 +853,8 @@ object.Mixin('PromiseMixin', 'soft', {
 	iter: IterablePromise,
 	interactive: InteractivePromise,
 	cooperative: CooperativePromise,
-	// XXX
-	//maybe: MaybePromise,
+	// XXX EXPEREMENTAL...
+	maybe: MaybePromise,
 	
 	// XXX need error support...
 	awaitOrRun: function(data, func){
diff --git a/README.md b/README.md
index 547ac6a..6a44264 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,9 @@ Library of JavaScript type extensions, types and utilities.
     - [Promise proxies](#promise-proxies)
       - [`<promise>.as(..)`](#promiseas)
       - [`<promise-proxy>.<method>(..)`](#promise-proxymethod)
+    - [Sync/Async promise](#syncasync-promise)
+      - [`Promise.maybe(..)` / `promise.MaybePromice(..)`](#promisemaybe--promisemaybepromice)
+      - [`<maybe-promise>.value` / `<maybe-promise>.error`](#maybe-promisevalue--maybe-promiseerror)
     - [Promise utilities](#promise-utilities)
       - [`Promise.awaitOrRun(..)`](#promiseawaitorrun)
   - [Generator extensions and utilities](#generator-extensions-and-utilities)
@@ -2001,6 +2004,18 @@ the main `<promise>` is resolved.
 
 
 
+### Sync/async promise
+
+
+#### `Promise.maybe(..)` / `promise.MaybePromice(..)`
+
+XXX
+
+#### `<maybe-promise>.value` / `<maybe-promise>.error`
+
+XXX
+
+
 ### Promise utilities
 
 #### `Promise.awaitOrRun(..)`
diff --git a/package.json b/package.json
index c97e912..a6a6fc6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ig-types",
-  "version": "6.22.2",
+  "version": "6.23.0",
   "description": "Generic JavaScript types and type extensions...",
   "main": "main.js",
   "scripts": {