diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,9 @@
+1.15.5
+------
+* Added `Metric` instances for `[]`, `ZipList`, `Maybe`
+* Added `det44` and `inv44` to `Linear.Matrix`
+* Added `Data` instance for `Point`
+
 1.15.4
 ------
 * Added Typeable and Data instances for V
diff --git a/linear.cabal b/linear.cabal
--- a/linear.cabal
+++ b/linear.cabal
@@ -1,6 +1,6 @@
 name:          linear
 category:      Math, Algebra
-version:       1.15.4
+version:       1.15.5
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
diff --git a/src/Linear/Affine.hs b/src/Linear/Affine.hs
--- a/src/Linear/Affine.hs
+++ b/src/Linear/Affine.hs
@@ -11,6 +11,11 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE DeriveGeneric #-}
 #endif
+{-# LANGUAGE DeriveDataTypeable #-}
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 708
+{-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+#endif
 -----------------------------------------------------------------------------
 -- |
 -- License     :  BSD-style (see the file LICENSE)
@@ -25,6 +30,7 @@
 import Control.Applicative
 import Control.Lens
 import Data.Complex (Complex)
+import Data.Data
 import Data.Distributive
 import Data.Foldable as Foldable
 import Data.Functor.Bind
@@ -128,8 +134,19 @@
 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 706
            , Generic1
 #endif
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 708
+           , Typeable, Data
+#endif
            )
 
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 708
+instance forall f. Typeable1 f => Typeable1 (Point f) where
+  typeOf1 _ = mkTyConApp (mkTyCon3 "linear" "Linear.Affine" "Point") [] `mkAppTy`
+              typeOf1 (undefined :: f a)
+
+deriving instance (Data (f a), Typeable1 f, Typeable a) => Data (Point f a)
+#endif
+
 lensP :: Lens' (Point g a) (g a)
 lensP afb (P a) = P <$> afb a
 {-# INLINE lensP #-}
@@ -163,7 +180,7 @@
 instance Ixed (f a) => Ixed (Point f a) where
   ix l = lensP . ix l
   {-# INLINE ix #-}
-  
+
 instance Traversable f => Each (Point f a) (Point f b) a b where
   each = traverse
   {-# INLINE each #-}
diff --git a/src/Linear/Matrix.hs b/src/Linear/Matrix.hs
--- a/src/Linear/Matrix.hs
+++ b/src/Linear/Matrix.hs
@@ -4,6 +4,10 @@
 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
 {-# LANGUAGE Trustworthy #-}
 #endif
+
+#ifdef HLINT
+{-# ANN module "HLint: ignore Reduce duplication" #-}
+#endif
 ---------------------------------------------------------------------------
 -- |
 -- Copyright   :  (C) 2012-2013 Edward Kmett,
@@ -21,7 +25,7 @@
   , adjoint
   , M22, M23, M24, M32, M33, M34, M42, M43, M44
   , m33_to_m44, m43_to_m44
-  , det22, det33, inv22, inv33
+  , det22, det33, det44, inv22, inv33, inv44
   , eye2, eye3, eye4
   , Trace(..)
   , translation
@@ -34,6 +38,7 @@
 import Control.Applicative
 import Control.Lens hiding (index)
 import Control.Lens.Internal.Context
+import Control.Monad (guard)
 import Data.Distributive
 import Data.Foldable as Foldable
 import Data.Functor.Rep
@@ -264,6 +269,29 @@
           (V3 g h i)) = a * (e*i-f*h) - d * (b*i-c*h) + g * (b*f-c*e)
 {-# INLINE det33 #-}
 
+-- |4x4 matrix determinant.
+det44 :: Num a => M44 a -> a
+det44 (V4 (V4 i00 i01 i02 i03)
+          (V4 i10 i11 i12 i13)
+          (V4 i20 i21 i22 i23)
+          (V4 i30 i31 i32 i33)) =
+  let
+    s0 = i00 * i11 - i10 * i01
+    s1 = i00 * i12 - i10 * i02
+    s2 = i00 * i13 - i10 * i03
+    s3 = i01 * i12 - i11 * i02
+    s4 = i01 * i13 - i11 * i03
+    s5 = i02 * i13 - i12 * i03
+
+    c5 = i22 * i33 - i32 * i23
+    c4 = i21 * i33 - i31 * i23
+    c3 = i21 * i32 - i31 * i22
+    c2 = i20 * i33 - i30 * i23
+    c1 = i20 * i32 - i30 * i22
+    c0 = i20 * i31 - i30 * i21
+  in s0 * c5 - s1 * c4 + s2 * c3 + s3 * c2 - s4 * c1 + s5 * c0
+{-# INLINE det44 #-}
+
 -- |2x2 matrix inverse.
 --
 -- >>> inv22 $ V2 (V2 1 2) (V2 3 4)
@@ -307,3 +335,44 @@
 -- V2 (V3 1 3 5) (V3 2 4 6)
 transpose :: (Distributive g, Functor f) => f (g a) -> g (f a)
 transpose = distribute
+{-# INLINE transpose #-}
+
+-- |4x4 matrix inverse.
+inv44 :: (Epsilon a, Fractional a) => M44 a -> Maybe (M44 a)
+inv44 (V4 (V4 i00 i01 i02 i03)
+          (V4 i10 i11 i12 i13)
+          (V4 i20 i21 i22 i23)
+          (V4 i30 i31 i32 i33)) =
+  let s0 = i00 * i11 - i10 * i01
+      s1 = i00 * i12 - i10 * i02
+      s2 = i00 * i13 - i10 * i03
+      s3 = i01 * i12 - i11 * i02
+      s4 = i01 * i13 - i11 * i03
+      s5 = i02 * i13 - i12 * i03
+      c5 = i22 * i33 - i32 * i23
+      c4 = i21 * i33 - i31 * i23
+      c3 = i21 * i32 - i31 * i22
+      c2 = i20 * i33 - i30 * i23
+      c1 = i20 * i32 - i30 * i22
+      c0 = i20 * i31 - i30 * i21
+      det = s0 * c5 - s1 * c4 + s2 * c3 + s3 * c2 - s4 * c1 + s5 * c0
+      invDet = recip det
+  in do guard (not (nearZero det))
+        return (invDet *!!
+                V4 (V4 (i11 * c5 - i12 * c4 + i13 * c3)
+                       (-i01 * c5 + i02 * c4 - i03 * c3)
+                       (i31 * s5 - i32 * s4 + i33 * s3)
+                       (-i21 * s5 + i22 * s4 - i23 * s3))
+                   (V4 (-i10 * c5 + i12 * c2 - i13 * c1)
+                       (i00 * c5 - i02 * c2 + i03 * c1)
+                       (-i30 * s5 + i32 * s2 - i33 * s1)
+                       (i20 * s5 - i22 * s2 + i23 * s1))
+                   (V4 (i10 * c4 - i11 * c2 + i13 * c0)
+                       (-i00 * c4 + i01 * c2 - i03 * c0)
+                       (i30 * s4 - i31 * s2 + i33 * s0)
+                       (-i20 * s4 + i21 * s2 - i23 * s0))
+                   (V4 (-i10 * c3 + i11 * c1 - i12 * c0)
+                       (i00 * c3 - i01 * c1 + i02 * c0)
+                       (-i30 * s3 + i31 * s1 - i32 * s0)
+                       (i20 * s3 - i21 * s1 + i22 * s0)))
+{-# INLINE inv44 #-}
diff --git a/src/Linear/Metric.hs b/src/Linear/Metric.hs
--- a/src/Linear/Metric.hs
+++ b/src/Linear/Metric.hs
@@ -18,6 +18,7 @@
   ( Metric(..), normalize, project
   ) where
 
+import Control.Applicative
 import Data.Foldable as Foldable
 import Data.Functor.Identity
 import Data.Vector (Vector)
@@ -68,6 +69,14 @@
 
 instance Metric Identity where
   dot (Identity x) (Identity y) = x * y
+
+instance Metric []
+
+instance Metric Maybe
+
+instance Metric ZipList where
+  -- ZipList is missing its Foldable instance
+  dot (ZipList x) (ZipList y) = dot x y
 
 instance Metric IntMap
 
diff --git a/src/Linear/V.hs b/src/Linear/V.hs
--- a/src/Linear/V.hs
+++ b/src/Linear/V.hs
@@ -74,6 +74,11 @@
 import Linear.Metric
 import Linear.Vector
 
+
+#ifdef HLINT
+{-# ANN module "hlint: ignore Eta reduce" #-}
+#endif
+
 class Dim n where
   reflectDim :: p n -> Int
 
@@ -327,3 +332,4 @@
     _ -> error "gunfold"
   dataTypeOf _ = vDataType
   dataCast1 f = gcast1 f
+