diff --git a/Nu/Nu/Nu/Nu.fsproj b/Nu/Nu/Nu/Nu.fsproj
index 420a898038..2195af4bf9 100644
--- a/Nu/Nu/Nu/Nu.fsproj
+++ b/Nu/Nu/Nu/Nu.fsproj
@@ -66,7 +66,6 @@
     <Compile Include="Constants.fs" />
     <Compile Include="Address.fs" />
     <Compile Include="Math.fs" />
-    <Compile Include="Xtension.fs" />
     <Compile Include="Overlayer.fs" />
     <Compile Include="OverlayRouter.fs" />
     <Compile Include="Reflection.fs" />
@@ -97,7 +96,7 @@
     <Compile Include="Observation.fs" />
     <Compile Include="Chain.fs" />
     <Compile Include="AddressTests.fs" />
-    <Compile Include="XtensionTests.fs" />
+    <Compile Include="ReflectionTests.fs" />
     <Compile Include="WorldTests.fs" />
     <Compile Include="ObservationTests.fs" />
     <Compile Include="ChainTests.fs" />
diff --git a/Nu/Nu/Nu/XtensionTests.fs b/Nu/Nu/Nu/ReflectionTests.fs
similarity index 65%
rename from Nu/Nu/Nu/XtensionTests.fs
rename to Nu/Nu/Nu/ReflectionTests.fs
index fb35552d10..d3e0f684bf 100644
--- a/Nu/Nu/Nu/XtensionTests.fs
+++ b/Nu/Nu/Nu/ReflectionTests.fs
@@ -9,7 +9,7 @@ open Xunit
 open Prime
 open Nu
 open Nu.Constants
-module XtensionTests =
+module ReflectionTests =
 
     type [<CLIMutable; NoComparison>] TestXtended =
         { Xtension : Xtension }
@@ -38,35 +38,6 @@ module XtensionTests =
         let xmlDocument = let emptyDoc = XmlDocument () in (emptyDoc.Load xmlReader; emptyDoc)
         read (xmlDocument.SelectSingleNode RootNodeName) target
 
-    let [<Fact>] canAddField () =
-        let xtn = Xtension.empty
-        let xtn = xtn?TestField <- 5
-        let fieldValue = xtn?TestField
-        Assert.Equal (5, fieldValue)
-
-#if DEBUG
-    let [<Fact>] cantAddFieldWhenSealed () =
-        let xtn = Xtension.safe
-        Assert.Throws<Exception> (fun () -> ignore <| xtn?TestField <- 0)
-#endif
-
-    let [<Fact>] cantAccessNonexistentField () =
-        let xtn = Xtension.mixed
-        let xtn = xtn?TestField <- 5
-        Assert.Throws<Exception> (fun () -> ignore <| xtn?TetField)
-
-    let [<Fact>] missingFieldReturnsDefault () =
-        let xtn = Xtension.empty
-        let xtn = xtn?TestField <- 0
-        let fieldValue = xtn?MissingField
-        Assert.Equal (0, fieldValue)
-
-    let [<Fact>] canAddFieldViaContainingType () =
-        let xtd = { Xtension = Xtension.empty }
-        let xtd = xtd?TestField <- 5
-        let fieldValue = xtd?TestField
-        Assert.Equal (5, fieldValue)
-
     let [<Fact>] xtensionSerializationViaContainingTypeWorks () =
         let xtd = { Xtension = Xtension.mixed }
         let xtd = xtd?TestField <- 5
diff --git a/Prime/Prime/Prime/Prime.fsproj b/Prime/Prime/Prime/Prime.fsproj
index 3f1d37984c..f2a3a20dc2 100644
--- a/Prime/Prime/Prime/Prime.fsproj
+++ b/Prime/Prime/Prime/Prime.fsproj
@@ -86,12 +86,14 @@
     <Compile Include="AlgebraicConverter.fs" />
     <Compile Include="AlgebraicDescriptor.fs" />
     <Compile Include="AlgebraicString.fs" />
+    <Compile Include="Xtension.fs" />
     <Compile Include="Implicit.fs" />
     <Compile Include="DuckTyping.fs" />
     <Compile Include="ImmutableSubclass.fs" />
     <Compile Include="RandTests.fs" />
     <Compile Include="AlgebraicReaderTests.fs" />
     <Compile Include="AlgebraicConverterTests.fs" />
+    <Compile Include="XtensionTests.fs" />
     <Compile Include="Program.fs" />
     <None Include="Interactive.fsx" />
     <None Include="App.config" />
diff --git a/Nu/Nu/Nu/Xtension.fs b/Prime/Prime/Prime/Xtension.fs
similarity index 97%
rename from Nu/Nu/Nu/Xtension.fs
rename to Prime/Prime/Prime/Xtension.fs
index f47008b601..d0b68d0e92 100644
--- a/Nu/Nu/Nu/Xtension.fs
+++ b/Prime/Prime/Prime/Xtension.fs
@@ -1,13 +1,11 @@
-// Nu Game Engine.
-// Copyright (C) Bryan Edds, 2013-2015.
+// Prime - A PRIMitivEs code library.
+// Copyright (C) Bryan Edds, 2012-2015.
 
-namespace Nu
+namespace Prime
 open System
 open System.Reflection
 open System.ComponentModel
 open Prime
-open Nu
-open Nu.Constants
 
 [<AutoOpen>]
 module XtensionModule =
diff --git a/Prime/Prime/Prime/XtensionTests.fs b/Prime/Prime/Prime/XtensionTests.fs
new file mode 100644
index 0000000000..aa4e411698
--- /dev/null
+++ b/Prime/Prime/Prime/XtensionTests.fs
@@ -0,0 +1,49 @@
+// Prime - A PRIMitivEs code library.
+// Copyright (C) Bryan Edds, 2012-2015.
+
+namespace Prime
+open System
+open System.IO
+open System.Xml
+open Xunit
+open Prime
+module XtensionTests =
+
+    type [<CLIMutable; NoComparison>] TestXtended =
+        { Xtension : Xtension }
+
+        static member (?) (this : TestXtended, memberName) =
+            Xtension.(?) (this.Xtension, memberName)
+
+        static member (?<-) (this : TestXtended, memberName, value) =
+            let xtension = Xtension.(?<-) (this.Xtension, memberName, value)
+            { this with Xtension = xtension }
+
+    let [<Fact>] canAddField () =
+        let xtn = Xtension.empty
+        let xtn = xtn?TestField <- 5
+        let fieldValue = xtn?TestField
+        Assert.Equal (5, fieldValue)
+
+#if DEBUG
+    let [<Fact>] cantAddFieldWhenSealed () =
+        let xtn = Xtension.safe
+        Assert.Throws<Exception> (fun () -> ignore <| xtn?TestField <- 0)
+#endif
+
+    let [<Fact>] cantAccessNonexistentField () =
+        let xtn = Xtension.mixed
+        let xtn = xtn?TestField <- 5
+        Assert.Throws<Exception> (fun () -> ignore <| xtn?TetField)
+
+    let [<Fact>] missingFieldReturnsDefault () =
+        let xtn = Xtension.empty
+        let xtn = xtn?TestField <- 0
+        let fieldValue = xtn?MissingField
+        Assert.Equal (0, fieldValue)
+
+    let [<Fact>] canAddFieldViaContainingType () =
+        let xtd = { Xtension = Xtension.empty }
+        let xtd = xtd?TestField <- 5
+        let fieldValue = xtd?TestField
+        Assert.Equal (5, fieldValue)
\ No newline at end of file