diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8fa63bc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+pkg/*
+Gemfile.lock
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..fa75df1
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,3 @@
+source 'https://rubygems.org'
+
+gemspec
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c05b809
--- /dev/null
+++ b/README.md
@@ -0,0 +1,52 @@
+[![Version     ](https://img.shields.io/gem/v/windsp.svg)](https://rubygems.org/gems/windsp)
+WinDSP
+======
+
+This software is published at https://github.com/unak/windsp .
+
+
+What's This?
+------------
+
+`/dev/dsp` emulator for Windows.
+
+
+Requirement
+-----------
+
+Ruby 2.0.0 or later.
+
+And, of cource, Windows :-)
+
+
+How to Use
+----------
+
+Simply require it.
+After requiring, you can write PCM to pseudo I/O via `open "/dev/dsp"`.
+
+
+License
+-------
+
+Copyright (c) 2015 NAKAMURA Usaku usa@garbagecollect.jp
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Rakefile b/Rakefile
new file mode 100644
index 0000000..cad27d2
--- /dev/null
+++ b/Rakefile
@@ -0,0 +1,2 @@
+# -*- Ruby -*-
+require "bundler/gem_tasks"
diff --git a/lib/windsp.rb b/lib/windsp.rb
new file mode 100644
index 0000000..ea38aa0
--- /dev/null
+++ b/lib/windsp.rb
@@ -0,0 +1,98 @@
+require 'fiddle/import'
+
+class WinDSP
+  module WinMM
+    extend Fiddle::Importer
+    dlload "winmm.dll"
+    extern "int PlaySound(void *, void *, long)"
+
+    SND_SYNC = 0x0000
+    SND_ASYNC = 0x0001
+    SND_NODEFAULT = 0x0002
+    SND_MEMORY = 0x0004
+    SND_LOOP = 0x0008
+    SND_NOSTOP = 0x0010
+    SND_NOWAIT = 0x00002000
+    SND_ALIAS = 0x00010000
+    SND_ALIAS_ID = 0x00110000
+    SND_FILENAME = 0x00020000
+    SND_RESOURCE = 0x00040004
+    SND_PURGE = 0x0040
+    SND_APPLICATION = 0x0080
+    SND_SENTRY = 0x00080000
+    SND_RING = 0x00100000
+    SND_SYSTEM = 0x00200000
+
+    def self.make_wave(pcm)
+      head = ["WAVEfmt ", 16, 1, 1, 8000, 8000 * 1 * 1, 1 * 1, 8].pack('a*VvvVVvv')
+      data = ["data", pcm.bytesize, pcm].pack('a*Va*')
+      ["RIFF", head.bytesize + data.bytesize, head, data].pack('a*Va*a*')
+    end
+
+    def self.play_pcm(pcm, sync: true)
+      flags = SND_NODEFAULT | SND_MEMORY
+      flags |= SND_ASYNC unless sync
+      PlaySound(make_wave(pcm), nil, flags)
+    end
+  end
+
+  VERSION = "0.0.1"
+
+  def self.open(*rest, &block)
+    io = self.new(rest)
+    if block
+      begin
+        block.call(io)
+      ensure
+        io.close
+      end
+    else
+      io
+    end
+  end
+
+  def initialize(*rest)
+    @buf = ""
+  end
+
+  def close
+    flush
+    WinMM.PlaySound(nil, nil, 0)
+  end
+
+  def flush
+    if @buf.bytesize >= 0
+      until WinMM.play_pcm(@buf, sync: false)
+        sleep 0.1
+      end
+    end
+    @buf = ""
+    WinMM.play_pcm("", sync: true)
+  end
+
+  def write(str)
+    @buf << str
+    flush if @buf.bytesize > 8000 * 1 * 1 * 4
+  end
+
+  alias binwrite write
+  alias print write
+  alias syswrite write
+  alias << write
+end
+
+module Kernel
+  private
+  alias windsp_orig_open open
+  class << self
+    alias windsp_orig_open open
+  end
+  def open(name, *rest, &block)
+    if name == "/dev/dsp"
+      WinDSP.open(*rest, &block)
+    else
+      windsp_orig_open(name, *rest, &block)
+    end
+  end
+  module_function :open
+end
diff --git a/windsp.gemspec b/windsp.gemspec
new file mode 100644
index 0000000..0c53592
--- /dev/null
+++ b/windsp.gemspec
@@ -0,0 +1,22 @@
+# coding: utf-8
+# -*- Ruby -*-
+require File.expand_path("lib/windsp")
+
+Gem::Specification.new do |spec|
+  spec.name          = "windsp"
+  spec.version       = WinDSP::VERSION
+  spec.authors       = ["U.Nakamura"]
+  spec.email         = ["usa@garbagecollect.jp"]
+  spec.description   = %q{`/dev/dsp` emulator for Windows}
+  spec.summary       = %q{`/dev/dsp` emulator for Windows}
+  spec.homepage      = "https://github.com/unak/windsp"
+  spec.license       = "BSD-2-Clause"
+
+  spec.files         = `git ls-files`.split($/)
+  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
+  spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
+  spec.require_paths = ["lib"]
+
+  spec.add_development_dependency "bundler", "~> 1.3"
+  spec.add_development_dependency "rake"
+end