diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,17 @@
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,6 @@
+module Main ( main ) where
+
+import Distribution.Simple
+
+main :: IO ()
+main = defaultMain
diff --git a/opentheory-fibonacci.cabal b/opentheory-fibonacci.cabal
new file mode 100644
--- /dev/null
+++ b/opentheory-fibonacci.cabal
@@ -0,0 +1,37 @@
+name: opentheory-fibonacci
+version: 1.69
+category: Number Theory
+synopsis: Fibonacci numbers
+license: MIT
+license-file: LICENSE
+cabal-version: >= 1.8.0.2
+build-type: Simple
+author: Joe Leslie-Hurd <joe@gilith.com>
+maintainer: Joe Leslie-Hurd <joe@gilith.com>
+description:
+  Fibonacci numbers - this package was automatically generated from the
+  OpenTheory package natural-fibonacci-1.69
+
+library
+  build-depends:
+    base >= 4.0 && < 5.0,
+    QuickCheck >= 2.4.0.1 && < 3.0,
+    opentheory-primitive >= 1.6 && < 2.0,
+    opentheory >= 1.195 && < 1.201,
+    opentheory-stream >= 1.46 && < 1.47
+  hs-source-dirs: src
+  ghc-options: -Wall
+  exposed-modules:
+    OpenTheory.Natural.Fibonacci
+
+test-suite opentheory-fibonacci-test
+  type: exitcode-stdio-1.0
+  build-depends:
+    base >= 4.0 && < 5.0,
+    QuickCheck >= 2.4.0.1 && < 3.0,
+    opentheory-primitive >= 1.6 && < 2.0,
+    opentheory >= 1.195 && < 1.201,
+    opentheory-stream >= 1.46 && < 1.47
+  hs-source-dirs: src
+  ghc-options: -Wall
+  main-is: Test.hs
diff --git a/src/OpenTheory/Natural/Fibonacci.hs b/src/OpenTheory/Natural/Fibonacci.hs
new file mode 100644
--- /dev/null
+++ b/src/OpenTheory/Natural/Fibonacci.hs
@@ -0,0 +1,50 @@
+{- |
+module: $Header$
+description: Fibonacci numbers
+license: MIT
+
+maintainer: Joe Leslie-Hurd <joe@gilith.com>
+stability: provisional
+portability: portable
+-}
+
+module OpenTheory.Natural.Fibonacci
+where
+
+import qualified Data.List as List
+import qualified OpenTheory.Primitive.Natural as Natural
+import qualified OpenTheory.Stream as Stream
+
+fibonaccis :: [Natural.Natural]
+fibonaccis = Stream.unfold (\(p, f) -> (p, (f, p + f))) (0, 1)
+
+decode :: [Bool] -> Natural.Natural
+decode =
+  dest 1 0
+  where
+  {-dest ::
+        Natural.Natural -> Natural.Natural -> [Bool] -> Natural.Natural-}
+    dest _ _ [] = 0
+    dest f p (h : t) =
+      let s = f + p in let n = dest s f t in if h then s + n else n
+
+encode :: Natural.Natural -> [Bool]
+encode =
+  \n -> find n 1 0
+  where
+  {-find ::
+        Natural.Natural -> Natural.Natural -> Natural.Natural -> [Bool]-}
+    find n f p = let s = f + p in if n < s then mk [] n f p else find n s f
+
+  {-mk ::
+        [Bool] -> Natural.Natural -> Natural.Natural -> Natural.Natural ->
+          [Bool]-}
+    mk l n f p =
+      if p == 0 then l
+      else if f <= n then mk (True : l) (n - f) p (f - p)
+      else mk (False : l) n p (f - p)
+
+zeckendorf :: [Bool] -> Bool
+zeckendorf [] = True
+zeckendorf (h : t) =
+  if List.null t then h else not (h && head t) && zeckendorf t
diff --git a/src/Test.hs b/src/Test.hs
new file mode 100644
--- /dev/null
+++ b/src/Test.hs
@@ -0,0 +1,37 @@
+{- |
+module: Main
+description: Fibonacci numbers - testing
+license: MIT
+
+maintainer: Joe Leslie-Hurd <joe@gilith.com>
+stability: provisional
+portability: portable
+-}
+module Main
+  ( main )
+where
+
+import qualified OpenTheory.Natural.Fibonacci as Fibonacci
+import qualified OpenTheory.Primitive.Natural as Natural
+import qualified OpenTheory.Stream as Stream
+import OpenTheory.Primitive.Test
+
+proposition0 :: Natural.Natural -> Bool
+proposition0 n = Fibonacci.zeckendorf (Fibonacci.encode n)
+
+proposition1 :: Natural.Natural -> Bool
+proposition1 n = Fibonacci.decode (Fibonacci.encode n) == n
+
+proposition2 :: Natural.Natural -> Natural.Natural -> Bool
+proposition2 j k =
+  Stream.nth Fibonacci.fibonaccis (j + (k + 1)) ==
+  Stream.nth Fibonacci.fibonaccis j * Stream.nth Fibonacci.fibonaccis k +
+  Stream.nth Fibonacci.fibonaccis (j + 1) *
+  Stream.nth Fibonacci.fibonaccis (k + 1)
+
+main :: IO ()
+main =
+    do check "Proposition 0:\n  !n. zeckendorf (encode n)\n  " proposition0
+       check "Proposition 1:\n  !n. decode (encode n) = n\n  " proposition1
+       check "Proposition 2:\n  !j k.\n    nth all (j + (k + 1)) =\n    nth all j * nth all k + nth all (j + 1) * nth all (k + 1)\n  " proposition2
+       return ()