diff --git a/README.md b/README.md
index 6d5f774..fb6d9d6 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,14 @@ Dotzip.decode(file)
  * https://pkware.cachefly.net/webdocs/APPNOTE/APPNOTE-6.3.3.TXT
  * https://en.wikipedia.org/wiki/ZIP_(file_format)
 
+### Other implementation
+
+ * http://infozip.sourceforge.net/
+ * https://github.com/kuba--/zip
+ * https://github.com/zip-rs/zip
+ * https://github.com/Stuk/jszip
+ * https://github.com/srikanth-lingala/zip4j
+
 ## Trademarks
 
 > PKWARE, PKZIP, SecureZIP, and PKSFX are registered trademarks of
diff --git a/lib/dotzip.ex b/lib/dotzip.ex
index 316f07c..946be1f 100644
--- a/lib/dotzip.ex
+++ b/lib/dotzip.ex
@@ -1,8 +1,10 @@
 defmodule Dotzip do
   
   @moduledoc """
-  Elixir Implementation of ZIP File Format. https://pkware.cachefly.net/webdocs/APPNOTE/APPNOTE-6.3.3.TXT
-  """
+
+  Elixir Implementation of ZIP File Format.
+
+  """  
 
   def decode(data) do
     {:ok, local, rest} = Dotzip.LocalFileHeader.decode(data)
diff --git a/lib/dotzip/extra_field.ex b/lib/dotzip/extra_field.ex
new file mode 100644
index 0000000..af3cdff
--- /dev/null
+++ b/lib/dotzip/extra_field.ex
@@ -0,0 +1,9 @@
+defmodule Dotzip.ExtraField do
+
+  def encode() do
+  end
+
+  def decode() do
+  end
+  
+end
diff --git a/lib/dotzip/extra_field/unix.ex b/lib/dotzip/extra_field/unix.ex
new file mode 100644
index 0000000..c071146
--- /dev/null
+++ b/lib/dotzip/extra_field/unix.ex
@@ -0,0 +1,104 @@
+defmodule Dotzip.ExtraField.Unix do
+
+  @moduledoc """
+  
+  This module encode and decode Unix extra field defined in section
+  4.5.7 of the official documentation.
+
+  """
+
+  defstruct atime: 0, mtime: 0, uid: 0, gid: 0, var: 0
+  
+  defp tag() do
+    <<0x00, 0x0d>>
+  end
+  
+  defp encode_tag({:ok, data, buffer}) do
+    {:ok, data, <<tag::binary-size(2), buffer::bitstring>>}
+  end
+
+  defp encode_tsize({:ok, data, buffer}) do
+    s = byte_size(buffer)
+    {:ok, data, <<s::size(16), buffer::bitstring>>}
+  end
+
+  defp encode_atime({:ok, %{ :atime => atime } = data, buffer}) do
+    {:ok, data, <<atime::size(32), buffer::bitstring>>}
+  end
+
+  defp encode_mtime({:ok, %{ :mtime => mtime } = data, buffer}) do
+    {:ok, data, <<mtime::size(32), buffer::bitstring>>}
+  end
+
+  defp encode_uid({:ok, %{ :uid => uid } = data, buffer}) do
+    {:ok, data, <<uid::size(16), buffer::bitstring>>}
+  end
+
+  defp encode_gid({:ok, %{ :gid => gid } = data, buffer}) do
+    {:ok, data, <<gid::size(16), buffer::bitstring>>}
+  end
+
+  defp encode_var(data) do
+    {:ok, data, <<>>}
+  end
+
+  @doc """
+
+  Encode an Unix Extra field.
+
+  """
+  def encode(data) do
+    encode_var(data)
+    |> encode_gid()
+    |> encode_uid()
+    |> encode_mtime()
+    |> encode_atime()
+    |> encode_tsize()
+    |> encode_tag()
+  end
+
+  defp decode_tag(<<0x00, 0x0d, rest::bitstring>>) do
+    {:ok, %{}, rest}
+  end
+
+  defp decode_tsize({:ok, data, <<tsize::size(16), rest::bitstring>>}) do
+    {:ok, Map.put(data, :tsize, tsize), rest}
+  end
+
+  defp decode_atime({:ok, data, <<atime::size(32), rest::bitstring>>}) do
+    {:ok, Map.put(data, :atime, atime), rest}
+  end
+
+  defp decode_mtime({:ok, data, <<mtime::size(32), rest::bitstring>>}) do
+    {:ok, Map.put(data, :mtime, mtime), rest}
+  end
+
+  defp decode_uid({:ok, data, <<uid::size(16), rest::bitstring>>}) do
+    {:ok, Map.put(data, :uid, uid), rest}
+  end
+
+  defp decode_gid({:ok, data, <<gid::size(16), rest::bitstring>>}) do
+    {:ok, Map.put(data, :gid, gid ), rest}
+  end
+
+  defp decode_var({:ok, data, rest}) do
+    {:ok, data, rest}
+  end
+
+  @doc """
+
+  Decode an Unix Extra field.
+
+  """
+  
+  def decode(bitstring) do
+    decode_tag(bitstring)
+    |> decode_tsize()
+    |> decode_atime()
+    |> decode_mtime()
+    |> decode_uid()
+    |> decode_gid()
+    |> decode_var()
+  end
+
+end
diff --git a/lib/dotzip64.ex b/lib/dotzip64.ex
new file mode 100644
index 0000000..b32b558
--- /dev/null
+++ b/lib/dotzip64.ex
@@ -0,0 +1,10 @@
+defmodule Dotzip64 do
+  
+  @moduledoc """
+
+  Elixir Implementation of ZIP64 File Format.
+
+  """ 
+  
+end
+
diff --git a/mix.exs b/mix.exs
index 8c14dd3..d9063d4 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,22 +7,26 @@ defmodule Dotzip.MixProject do
       version: "0.1.0",
       elixir: "~> 1.11",
       start_permanent: Mix.env() == :prod,
-      deps: deps()
+      deps: deps(),
+
+      name: "DotZip",
+      source_url: "https://github.com/niamtokik/dotzip",
+      homepage_url: "https://github.com/niamtokik/dotzip",
+      docs: [
+        main: "DotZip"
+      ]
     ]
   end
 
-  # Run "mix help compile.app" to learn about applications.
   def application do
     [
       extra_applications: [:logger]
     ]
   end
 
-  # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+      {:ex_doc, "~> 0.24", only: :dev, runtime: false}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
new file mode 100644
index 0000000..04e17cd
--- /dev/null
+++ b/mix.lock
@@ -0,0 +1,8 @@
+%{
+  "earmark_parser": {:hex, :earmark_parser, "1.4.12", "b245e875ec0a311a342320da0551da407d9d2b65d98f7a9597ae078615af3449", [:mix], [], "hexpm", "711e2cc4d64abb7d566d43f54b78f7dc129308a63bc103fbd88550d2174b3160"},
+  "ex_doc": {:hex, :ex_doc, "0.24.2", "e4c26603830c1a2286dae45f4412a4d1980e1e89dc779fcd0181ed1d5a05c8d9", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "e134e1d9e821b8d9e4244687fb2ace58d479b67b282de5158333b0d57c6fb7da"},
+  "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.15.1", "b5888c880d17d1cc3e598f05cdb5b5a91b7b17ac4eaf5f297cb697663a1094dd", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.1", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "db68c173234b07ab2a07f645a5acdc117b9f99d69ebf521821d89690ae6c6ec8"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.1.0", "3a6fca1550363552e54c216debb6a9e95bd8d32348938e13de5eda962c0d7f89", [:mix], [], "hexpm", "08eb32d66b706e913ff748f11694b17981c0b04a33ef470e33e11b3d3ac8f54b"},
+}
diff --git a/test/dotzip/extra_field/unix_test.exs b/test/dotzip/extra_field/unix_test.exs
new file mode 100644
index 0000000..1a96194
--- /dev/null
+++ b/test/dotzip/extra_field/unix_test.exs
@@ -0,0 +1,17 @@
+defmodule Dotzip.ExtraField.UnixTest do
+  use ExUnit.Case, async: true
+
+  test "decode an empty Unix field" do
+    struct = %{atime: 0, gid: 0, mtime: 0, uid: 0, tsize: 12}
+    {:ok, struct, data} = Dotzip.ExtraField.Unix.encode(struct)
+    {:ok, decoded_struct, decoded_data} = Dotzip.ExtraField.Unix.decode(data)
+    assert struct == decoded_struct
+  end
+
+  test "encode an empty Unix field" do
+    data = <<0, 13, 0, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>>
+    {:ok, decoded_struct, _} = Dotzip.ExtraField.Unix.decode(data)
+    {:ok, struct, encoded_data} = Dotzip.ExtraField.Unix.encode(decoded_struct)
+    assert struct == decoded_struct
+  end
+end