diff --git a/MANIFEST b/MANIFEST
index 8d41fb2519..36b99b2175 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -120,6 +120,16 @@ lib/date/format.rb
 lib/date2.rb
 lib/debug.rb
 lib/delegate.rb
+lib/drb.rb
+lib/drb/drb.rb
+lib/drb/eq.rb
+lib/drb/extserv.rb
+lib/drb/extservm.rb
+lib/drb/gw.rb
+lib/drb/invokemethod.rb
+lib/drb/observer.rb
+lib/drb/timeridconv.rb
+lib/drb/unix.rb
 lib/e2mmap.rb
 lib/erb.rb
 lib/eregex.rb
diff --git a/lib/drb.rb b/lib/drb.rb
new file mode 100644
index 0000000000..93cc811e14
--- /dev/null
+++ b/lib/drb.rb
@@ -0,0 +1,2 @@
+require 'drb/drb'
+
diff --git a/lib/drb/drb.rb b/lib/drb/drb.rb
new file mode 100644
index 0000000000..85cd3bc898
--- /dev/null
+++ b/lib/drb/drb.rb
@@ -0,0 +1,854 @@
+=begin
+= distributed Ruby --- dRuby 2.0.4
+ 	Copyright (c) 1999-2003 Masatoshi SEKI 
+        You can redistribute it and/or modify it under the same terms as Ruby.
+=end
+
+require 'socket'
+require 'thread'
+require 'fcntl'
+
+module DRb
+  class DRbError < RuntimeError; end
+  class DRbConnError < DRbError; end
+
+  class DRbIdConv
+    def to_obj(ref)
+      ObjectSpace._id2ref(ref)
+    end
+    
+    def to_id(obj)
+      obj.nil? ? nil : obj.__id__
+    end
+  end
+
+  module DRbUndumped 
+    def _dump(dummy)
+      raise TypeError, 'can\'t dump'
+    end
+  end
+
+  class DRbServerNotFound < DRbError; end
+  class DRbBadURI < DRbError; end
+  class DRbBadScheme < DRbError; end
+
+  class DRbUnknownError < DRbError
+    def initialize(unknown)
+      @unknown = unknown
+      super(unknown.name)
+    end
+    attr_reader :unknown
+
+    def self._load(s)
+      Marshal::load(s)
+    end
+    
+    def _dump(lv)
+      Marshal::dump(@unknown)
+    end
+  end
+
+  class DRbUnknown
+    def initialize(err, buf)
+      case err
+      when /uninitialized constant (\S+)/
+	@name = $1
+      when /undefined class\/module (\S+)/
+	@name = $1
+      else
+	@name = nil
+      end
+      @buf = buf
+    end
+    attr_reader :name, :buf
+
+    def self._load(s)
+      begin
+	Marshal::load(s)
+      rescue NameError, ArgumentError
+	DRbUnknown.new($!, s)
+      end
+    end
+
+    def _dump(lv)
+      @buf
+    end
+
+    def reload
+      self.class._load(@buf)
+    end
+
+    def exception
+      DRbUnknownError.new(self)
+    end
+  end
+
+  class DRbMessage
+    def initialize(config)
+      @load_limit = config[:load_limit]
+      @argc_limit = config[:argc_limit]
+    end
+
+    def dump(obj)
+      obj = DRbObject.new(obj) if obj.kind_of? DRbUndumped
+      begin
+	str = Marshal::dump(obj)
+      rescue
+	str = Marshal::dump(DRbObject.new(obj))
+      end
+      [str.size].pack('N') + str
+    end
+
+    def load(soc)
+      sz = soc.read(4)	# sizeof (N)
+      raise(DRbConnError, 'connection closed') if sz.nil?
+      raise(DRbConnError, 'premature header') if sz.size < 4
+      sz = sz.unpack('N')[0]
+      raise(DRbConnError, "too large packet #{sz}") if @load_limit < sz
+      str = soc.read(sz)
+      raise(DRbConnError, 'connection closed') if sz.nil?
+      raise(DRbConnError, 'premature marshal format(can\'t read)') if str.size < sz
+      begin
+	Marshal::load(str)
+      rescue NameError, ArgumentError
+	DRbUnknown.new($!, str)
+      end
+    end
+
+    def send_request(stream, ref, msg_id, arg, b)
+      ary = []
+      ary.push(dump(ref.__drbref))
+      ary.push(dump(msg_id.id2name))
+      ary.push(dump(arg.length))
+      arg.each do |e|
+	ary.push(dump(e))
+      end
+      ary.push(dump(b))
+      stream.write(ary.join(''))
+    end
+    
+    def recv_request(stream)
+      ref = load(stream)
+      ro = DRb.to_obj(ref)
+      msg = load(stream)
+      argc = load(stream)
+      raise ArgumentError, 'too many arguments' if @argc_limit < argc
+      argv = Array.new(argc, nil)
+      argc.times do |n|
+	argv[n] = load(stream)
+      end
+      block = load(stream)
+      return ro, msg, argv, block
+    end
+
+    def send_reply(stream, succ, result)
+      stream.write(dump(succ) + dump(result))
+    end
+
+    def recv_reply(stream)
+      succ = load(stream)
+      result = load(stream)
+      [succ, result]
+    end
+  end
+
+  module DRbProtocol
+    module_function
+    def add_protocol(prot)
+      @protocol.push(prot)
+    end
+
+    module_function
+    def open(uri, config, first=true) 
+      @protocol.each do |prot|
+	begin
+	  return prot.open(uri, config)
+	rescue DRbBadScheme
+	rescue DRbConnError
+	  raise($!)
+	rescue
+	  raise(DRbConnError, "#{uri} - #{$!.inspect}")
+	end
+      end
+      if first && (config[:auto_load] != false)
+	auto_load(uri, config)
+	return open(uri, config, false)
+      end
+      raise DRbBadURI, 'can\'t parse uri:' + uri
+    end
+
+    module_function
+    def open_server(uri, config, first=true)
+      @protocol.each do |prot|
+	begin
+	  return prot.open_server(uri, config)
+	rescue DRbBadScheme
+	end
+      end
+      if first && (config[:auto_load] != false)
+	auto_load(uri, config)
+	return open_server(uri, config, false)
+      end
+      raise DRbBadURI, 'can\'t parse uri:' + uri
+    end
+
+    module_function
+    def uri_option(uri, config, first=true)
+      @protocol.each do |prot|
+	begin
+	  uri, opt = prot.uri_option(uri, config)
+	  # opt = nil if opt == ''
+	  return uri, opt
+	rescue DRbBadScheme
+	end
+      end
+      if first && (config[:auto_load] != false)
+	auto_load(uri, config)
+        return uri_option(uri, config, false)
+      end
+      raise DRbBadURI, 'can\'t parse uri:' + uri
+    end
+
+    module_function
+    def auto_load(uri, config)
+      if uri =~ /^drb([a-z0-9]+):/
+	require("drb/#{$1}") rescue nil
+      end
+    end
+  end
+
+  class DRbTCPSocket
+    private
+    def self.parse_uri(uri)
+      if uri =~ /^druby:\/\/(.*?):(\d+)(\?(.*))?$/
+	host = $1
+	port = $2.to_i
+	option = $4
+	[host, port, option]
+      else
+	raise(DRbBadScheme, uri) unless uri =~ /^druby:/
+	raise(DRbBadURI, 'can\'t parse uri:' + uri)
+      end
+    end
+
+    public
+    def self.open(uri, config)
+      host, port, option = parse_uri(uri)
+      host.untaint
+      port.untaint
+      soc = TCPSocket.open(host, port)
+      self.new(uri, soc, config)
+    end
+
+    def self.open_server(uri, config)
+      uri = 'druby://:0' unless uri
+      host, port, opt = parse_uri(uri)
+      if host.size == 0
+	soc = TCPServer.open(port)
+	host = Socket.gethostname
+      else
+	soc = TCPServer.open(host, port)
+      end
+      port = soc.addr[1] if port == 0
+      uri = "druby://#{host}:#{port}"
+      self.new(uri, soc, config)
+    end
+
+    def self.uri_option(uri, config)
+      host, port, option = parse_uri(uri)
+      return "druby://#{host}:#{port}", option
+    end
+
+    def initialize(uri, soc, config={})
+      @uri = uri
+      @socket = soc
+      @config = config
+      @acl = config[:tcp_acl]
+      @msg = DRbMessage.new(config)
+      set_sockopt(@socket)
+    end
+    attr_reader :uri
+
+    def peeraddr
+      @socket.peeraddr
+    end
+    
+    def stream; @socket; end
+
+    def send_request(ref, msg_id, arg, b)
+      @msg.send_request(stream, ref, msg_id, arg, b)
+    end
+    
+    def recv_request
+      @msg.recv_request(stream)
+    end
+
+    def send_reply(succ, result)
+      @msg.send_reply(stream, succ, result)
+    end
+
+    def recv_reply
+      @msg.recv_reply(stream)
+    end
+
+    public
+    def close
+      if @socket
+	@socket.close
+	@socket = nil
+      end
+    end
+    
+    def accept
+      while true
+	s = @socket.accept
+	break if (@acl ? @acl.allow_socket?(s) : true) 
+	s.close
+      end
+      self.class.new(nil, s, @config)
+    end
+
+    def alive?
+      return false unless @socket
+      if IO.select([@socket], nil, nil, 0)
+	close
+	return false
+      end
+      true
+    end
+
+    def set_sockopt(soc)
+      soc.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
+      soc.fcntl(Fcntl::F_SETFL, Fcntl::O_NONBLOCK) if defined? Fcntl::O_NONBLOCK
+      soc.fcntl(Fcntl::F_SETFL, Fcntl::FD_CLOEXEC) if defined? Fcntl::FD_CLOEXEC
+    end
+  end
+
+  module DRbProtocol
+    @protocol = [DRbTCPSocket] # default
+  end
+
+  class DRbURIOption
+    def initialize(option)
+      @option = option.to_s
+    end
+    attr :option
+    def to_s; @option; end
+    
+    def ==(other)
+      return false unless DRbURIOption === other
+      @option == other.option
+    end
+    
+    def hash
+      @option.hash
+    end
+    
+    alias eql? ==
+  end
+
+  class DRbObject
+    def self._load(s)
+      uri, ref = Marshal.load(s)
+      if DRb.here?(uri)
+	return DRb.to_obj(ref)
+      end
+
+      it = self.new(nil)
+      it.reinit(uri, ref)
+      it
+    end
+
+    def self.new_with_uri(uri)
+      self.new(nil, uri)
+    end
+
+    def _dump(lv)
+      Marshal.dump([@uri, @ref])
+    end
+
+    def initialize(obj, uri=nil)
+      @uri = nil
+      @ref = nil
+      if obj.nil?
+	return if uri.nil?
+	@uri, option = DRbProtocol.uri_option(uri, DRb.config)
+	@ref = DRbURIOption.new(option) unless option.nil?
+      else
+	@uri = uri ? uri : (DRb.uri rescue nil)
+	@ref = obj ? DRb.to_id(obj) : nil
+      end
+    end
+
+    def reinit(uri, ref)
+      @uri = uri
+      @ref = ref
+    end
+
+    def __drburi
+      @uri
+    end
+
+    def __drbref
+      @ref
+    end
+
+    undef :to_s
+    undef :to_a
+    undef :respond_to?
+
+    def method_missing(msg_id, *a, &b)
+      if DRb.here?(@uri)
+	obj = DRb.to_obj(@ref)
+	DRb.current_server.check_insecure_method(obj, msg_id)
+	return obj.__send__(msg_id, *a, &b) 
+      end
+
+      succ, result = DRbConn.open(@uri) do |conn|
+	conn.send_message(self, msg_id, a, b)
+      end
+      return result if succ
+      unless DRbUnknown === result
+	prefix = "(#{@uri}) "
+	bt = []
+	result.backtrace.each do |x|
+	  break if /`__send__'$/ =~ x 
+	  if /^\(druby:\/\// =~ x
+	    bt.push(x)
+	  else
+	    bt.push(prefix + x)
+	  end
+	end
+	raise result, result.message, bt + caller
+      else
+	raise result
+      end
+    end
+  end
+
+  class DRbConn
+    POOL_SIZE = 16
+    @mutex = Mutex.new
+    @pool = []
+
+    def self.open(remote_uri)
+      begin
+	conn = nil
+
+	@mutex.synchronize do
+	  #FIXME
+	  new_pool = []
+	  @pool.each do |c|
+	    if conn.nil? and c.uri == remote_uri
+	      conn = c if c.alive?
+	    else
+	      new_pool.push c
+	    end
+	  end
+	  @pool = new_pool
+	end
+
+	conn = self.new(remote_uri) unless conn
+	succ, result = yield(conn)
+	return succ, result
+
+      ensure
+	@mutex.synchronize do
+	  if @pool.size > POOL_SIZE or ! succ
+	    conn.close if conn
+	  else
+	    @pool.unshift(conn)
+	  end
+	end
+      end
+    end
+
+    def initialize(remote_uri)
+      @uri = remote_uri
+      @protocol = DRbProtocol.open(remote_uri, DRb.config)
+    end
+    attr_reader :uri
+
+    def send_message(ref, msg_id, arg, block)
+      @protocol.send_request(ref, msg_id, arg, block)
+      @protocol.recv_reply
+    end
+
+    def close
+      @protocol.close
+      @protocol = nil
+    end
+
+    def alive?
+      @protocol.alive?
+    end
+  end
+
+  class DRbServer
+    @@acl = nil
+    @@idconv = DRbIdConv.new
+    @@secondary_server = nil
+    @@argc_limit = 256
+    @@load_limit = 256 * 102400
+    @@verbose = false
+
+    def self.default_argc_limit(argc)
+      @@argc_limit = argc
+    end
+
+    def self.default_load_limit(sz)
+      @@load_limit = sz
+    end
+
+    def self.default_acl(acl)
+      @@acl = acl
+    end
+
+    def self.default_id_conv(idconv)
+      @@idconv = idconv
+    end
+
+    def self.verbose=(on)
+      @@verbose = on
+    end
+    
+    def self.verbose
+      @@verbose
+    end
+
+    def self.make_config(hash={})
+      default_config = { 
+	:idconv => @@idconv,
+	:verbose => @@verbose,
+	:tcp_acl => @@acl,
+	:load_limit => @@load_limit,
+	:argc_limit => @@argc_limit
+      }
+      default_config.update(hash)
+    end
+
+    def initialize(uri=nil, front=nil, config_or_acl=nil)
+      if Hash === config_or_acl
+	config = config_or_acl.dup
+      else
+	acl = config_or_acl || @@acl
+	config = {
+	  :tcp_acl => acl
+	}
+      end
+
+      @config = self.class.make_config(config)
+
+      @protocol = DRbProtocol.open_server(uri, @config)
+      @uri = @protocol.uri
+
+      @front = front
+      @idconv = @config[:idconv]
+
+      @grp = ThreadGroup.new
+      @thread = run
+
+      Thread.exclusive do
+	DRb.primary_server = self unless DRb.primary_server
+      end
+    end
+    attr_reader :uri, :thread, :front
+    attr_reader :config
+
+    def verbose=(v); @config[:verbose]=v; end
+    def verbose; @config[:verbose]; end
+
+    def alive?
+      @thread.alive?
+    end
+
+    def stop_service
+      @thread.kill
+    end
+
+    def to_obj(ref)
+      return front if ref.nil?
+      return front[ref.to_s] if DRbURIOption === ref
+      @idconv.to_obj(ref)
+    end
+
+    def to_id(obj)
+      return nil if obj.__id__ == front.__id__
+      @idconv.to_id(obj)
+    end
+
+    private
+    def kill_sub_thread
+      Thread.new do
+	grp = ThreadGroup.new
+	grp.add(Thread.current)
+	list = @grp.list
+	while list.size > 0
+	  list.each do |th|
+	    th.kill if th.alive?
+	  end
+	  list = @grp.list
+	end
+      end
+    end
+
+    def run
+      Thread.start do
+	begin
+	  while true
+	    main_loop
+	  end
+	ensure
+	  @protocol.close if @protocol
+	  kill_sub_thread
+	end
+      end
+    end
+
+    INSECURE_METHOD = [
+      :__send__
+    ]
+    def insecure_method?(msg_id)
+      INSECURE_METHOD.include?(msg_id)
+    end
+
+    def any_to_s(obj)
+      obj.to_s rescue sprintf("#<%s:0x%lx>", obj.class, obj.__id__)      
+    end
+
+    def check_insecure_method(obj, msg_id)
+      return true if Proc === obj && msg_id == :__drb_yield
+      raise(ArgumentError, "#{any_to_s(msg_id)} is not a symbol") unless Symbol == msg_id.class
+      raise(SecurityError, "insecure method `#{msg_id}'") if insecure_method?(msg_id)
+      unless obj.respond_to?(msg_id)
+	desc = any_to_s(obj)
+	if desc.nil? || desc[0] == '#'
+	  desc << ":#{obj.class}"
+	end
+	
+	if obj.private_methods.include?(msg_id.to_s)
+	  raise NameError, "private method `#{msg_id}' called for #{desc}"
+	else
+	  raise NameError, "undefined method `#{msg_id}' called for #{desc}"
+	end
+      end
+      true
+    end
+    public :check_insecure_method
+
+    class InvokeMethod
+      def initialize(drb_server, client)
+	@drb_server = drb_server
+	@client = client
+      end
+
+      def perform
+	@result = nil
+	@succ = false
+	setup_message
+        if @block
+          @result = perform_with_block
+        else
+          @result = perform_without_block
+        end
+	@succ = true
+	return @succ, @result
+      rescue StandardError, ScriptError, Interrupt
+	@result = $!
+	return @succ, @result
+      end
+
+      private
+      def init_with_client
+	obj, msg, argv, block = @client.recv_request
+        @obj = obj
+        @msg_id = msg.intern
+        @argv = argv
+        @block = block
+      end
+      
+      def check_insecure_method
+        @drb_server.check_insecure_method(@obj, @msg_id)
+      end
+
+      def setup_message
+	init_with_client
+	check_insecure_method
+      end
+      
+      def perform_without_block
+	if Proc === @obj && @msg_id == :__drb_yield
+          if @argv.size == 1
+	    ary = @argv
+	  else
+	    ary = [@argv]
+	  end
+	  ary.collect(&@obj)[0]
+	else
+	  @obj.__send__(@msg_id, *@argv)
+	end
+      end
+
+      def rescue_local_jump(err)
+	case err.message
+	when /^retry/	# retry from proc-closure
+	  return :retry
+	when /^break/	# break from proc-closure
+	  return rescue_break(err)
+	else
+	  return :unknown
+	end
+      end
+
+    end
+
+    if RUBY_VERSION >= '1.8'
+      require 'drb/invokemethod'
+      class InvokeMethod
+        include InvokeMethod18Mixin
+      end
+    else
+      module InvokeMethod16Mixin
+	def block_yield(x)
+          if x.class == Array
+	    block_value = @block.__drb_yield(*x)
+          else
+	    block_value = @block.__drb_yield(x)
+          end
+	end
+
+	def rescue_break(err)
+	  return :break
+	end
+
+	def perform_with_block
+	  @obj.__send__(@msg_id, *@argv) do |x|
+	    jump_error = nil
+	    begin
+	      block_value = block_yield(x)
+	    rescue LocalJumpError
+	      jump_error = $!
+	    end
+	    if jump_error
+	      reason ,= rescue_local_jump(jump_error)
+	      case reason
+	      when :retry
+		retry
+	      when :break
+		break
+	      else
+		raise jump_error
+	      end
+	    end
+	    block_value
+	  end
+	end
+      end
+
+      class InvokeMethod
+        include InvokeMethod16Mixin
+      end
+    end
+
+    def main_loop
+      Thread.start(@protocol.accept) do |client|
+	@grp.add Thread.current
+	Thread.current['DRb'] = { 'client' => client ,
+	                          'server' => self }
+	loop do
+	  begin
+	    succ = false
+	    invoke_method = InvokeMethod.new(self, client)
+	    succ, result = invoke_method.perform
+	    if !succ && verbose
+	      p result
+	      result.backtrace.each do |x|
+		puts x
+	      end
+	    end
+	    client.send_reply(succ, result) rescue nil
+	  ensure
+	    unless succ
+	      client.close
+	      return
+	    end
+	  end
+	end
+      end
+    end
+  end
+
+  @primary_server = nil
+
+  def start_service(uri=nil, front=nil, config=nil)
+    @primary_server = DRbServer.new(uri, front, config)
+  end
+  module_function :start_service
+
+  attr_accessor :primary_server
+  module_function :primary_server=, :primary_server
+
+  def current_server
+    drb = Thread.current['DRb'] 
+    server = (drb && drb['server']) ? drb['server'] : @primary_server 
+    raise DRbServerNotFound unless server
+    return server
+  end
+  module_function :current_server
+
+  def stop_service
+    @primary_server.stop_service if @primary_server
+    @primary_server = nil
+  end
+  module_function :stop_service
+
+  def uri
+    current_server.uri
+  end
+  module_function :uri
+
+  def here?(uri)
+    (current_server.uri rescue nil) == uri
+  end
+  module_function :here?
+
+  def config
+    current_server.config
+  rescue
+    DRbServer.make_config
+  end
+  module_function :config
+  
+  def front
+    current_server.front
+  end
+  module_function :front
+
+  def to_obj(ref)
+    current_server.to_obj(ref)
+  end
+  def to_id(obj)
+    current_server.to_id(obj)
+  end
+  module_function :to_id
+  module_function :to_obj
+
+  def thread
+    @primary_server ? @primary_server.thread : nil
+  end
+  module_function :thread
+
+  def install_id_conv(idconv)
+    DRbServer.default_id_conv(idconv)
+  end
+  module_function :install_id_conv
+
+  def install_acl(acl)
+    DRbServer.default_acl(acl)
+  end
+  module_function :install_acl
+end
+
+DRbObject = DRb::DRbObject
+DRbUndumped = DRb::DRbUndumped
+DRbIdConv = DRb::DRbIdConv
diff --git a/lib/drb/eq.rb b/lib/drb/eq.rb
new file mode 100644
index 0000000000..e24512d6a7
--- /dev/null
+++ b/lib/drb/eq.rb
@@ -0,0 +1,16 @@
+require 'drb/drb'
+
+module DRb
+  class DRbObject
+    def ==(other)
+      return false unless DRbObject === other
+     (@ref == other.__drbref) && (@uri == other.__drburi)
+    end
+
+    def hash
+      [@uri, @ref].hash
+    end
+
+    alias eql? ==
+  end
+end
diff --git a/lib/drb/extserv.rb b/lib/drb/extserv.rb
new file mode 100644
index 0000000000..f05bae5264
--- /dev/null
+++ b/lib/drb/extserv.rb
@@ -0,0 +1,67 @@
+=begin
+ external service
+ 	Copyright (c) 2000,2002 Masatoshi SEKI 
+=end
+
+require 'drb/drb'
+
+module DRb
+  class ExtServ
+    include DRbUndumped
+
+    def initialize(there, name, server=nil)
+      @server = server || DRb::primary_server
+      @name = name
+      ro = DRbObject.new(nil, there)
+      @invoker = ro.regist(name, DRbObject.new(self, @server.uri))
+    end
+    attr_reader :server
+
+    def front
+      DRbObject.new(nil, @server.uri)
+    end
+
+    def stop_service
+      @invoker.unregist(@name)
+      server = @server
+      @server = nil
+      Thread.new do
+	sleep 1
+	server.stop_service
+      end
+      true
+    end
+
+    def alive?
+      @server ? @server.alive? : false
+    end
+  end
+end
+
+if __FILE__ == $0
+  class Foo
+    include DRbUndumped
+
+    def initialize(str)
+      @str = str
+    end
+
+    def hello(it)
+      "#{it}: #{self}"
+    end
+
+    def to_s
+      @str
+    end
+  end
+
+  cmd = ARGV.shift
+  case cmd
+  when 'itest1', 'itest2'
+    front = Foo.new(cmd)
+    manager = DRb::DRbServer.new(nil, front)
+    es = DRb::ExtService.new(ARGV.shift, ARGV.shift, manager)
+    es.server.thread.join
+  end
+end
+
diff --git a/lib/drb/extservm.rb b/lib/drb/extservm.rb
new file mode 100644
index 0000000000..50009dbae2
--- /dev/null
+++ b/lib/drb/extservm.rb
@@ -0,0 +1,94 @@
+=begin
+ external service manager
+ 	Copyright (c) 2000 Masatoshi SEKI 
+=end
+
+require 'drb/drb'
+require 'thread'
+
+module DRb
+  class ExtServManager
+    include DRbUndumped
+
+    @@command = {}
+
+    def self.command
+      @@command
+    end
+
+    def self.command=(cmd)
+      @@command = cmd
+    end
+      
+    def initialize
+      @servers = {}
+      @waiting = []
+      @queue = Queue.new
+      @thread = invoke_thread
+    end
+    attr_reader :server
+
+    def service(name)
+      while true
+	server = nil
+	Thread.exclusive do
+	  server = @servers[name] if @servers[name]
+	end
+	return server if server && server.alive?
+	invoke_service(name)
+      end
+    end
+
+    def regist(name, ro)
+      ary = nil
+      Thread.exclusive do
+	@servers[name] = ro
+	ary = @waiting
+	@waiting = []
+      end
+      ary.each do |th|
+	begin
+	  th.run
+	rescue ThreadError
+	end
+      end
+      self
+    end
+    
+    def unregist(name)
+      Thread.exclusive do
+	@servers.delete(name)
+      end
+    end
+
+    private
+    def invoke_thread
+      Thread.new do
+	while true
+	  name = @queue.pop
+	  invoke_service_command(name, @@command[name])
+	end
+      end
+    end
+
+    def invoke_service(name)
+      Thread.critical = true
+      @waiting.push Thread.current
+      @queue.push name
+      Thread.stop
+    end
+
+    def invoke_service_command(name, command)
+      raise "invalid command. name: #{name}" unless command
+      Thread.exclusive do
+	return if @servers.include?(name)
+	@servers[name] = false
+      end
+      if RUBY_PLATFORM =~ /mswin32/
+	system("cmd /c start /b #{command} #{DRb.uri} #{name}")
+      else
+	system("#{command} #{DRb.uri} #{name} &")
+      end
+    end
+  end
+end
diff --git a/lib/drb/gw.rb b/lib/drb/gw.rb
new file mode 100644
index 0000000000..012a2b0a11
--- /dev/null
+++ b/lib/drb/gw.rb
@@ -0,0 +1,60 @@
+require 'drb/drb'
+require 'monitor'
+
+module DRb
+  class GWIdConv < DRbIdConv
+    def to_obj(ref)
+      if Array === ref && ref[0] == :DRbObject
+        it = DRbObject.new(nil)
+        it.reinit(ref[1], ref[2])
+        return it
+      end
+      super(ref)
+    end
+  end
+
+  class GW
+    include MonitorMixin
+    def initialize
+      super()
+      @hash = {}
+    end
+
+    def [](key)
+      synchronize do
+        @hash[key]
+      end
+    end
+
+    def []=(key, v)
+      synchronize do
+        @hash[key] = v
+      end
+    end
+  end
+
+  class DRbObject
+    def self._load(s)
+      uri, ref = Marshal.load(s)
+      if DRb.uri == uri
+        return ref ? DRb.to_obj(ref) : DRb.front
+      end
+
+      it = self.new(nil)
+      it.reinit(DRb.uri, [:DRbObject, uri, ref])
+      it
+    end
+
+    def _dump(lv)
+      if DRb.uri == @uri
+        if Array === @ref && @ref[0] == :DRbObject
+          Marshal.dump([@ref[1], @ref[2]])
+        else
+          Marshal.dump([@uri, @ref]) # ??
+        end
+      else
+        Marshal.dump([DRb.uri, [:DRbObject, @uri, @ref]])
+      end
+    end
+  end
+end
diff --git a/lib/drb/invokemethod.rb b/lib/drb/invokemethod.rb
new file mode 100644
index 0000000000..f8ce0ad09b
--- /dev/null
+++ b/lib/drb/invokemethod.rb
@@ -0,0 +1,39 @@
+
+# for ruby-1.8.0
+
+module DRb
+  class DRbServer
+    module InvokeMethod18Mixin
+      def block_yield(x)
+        block_value = @block.call(*x)
+      end
+      
+      def rescue_break(err)
+        return :break, err.exit_value
+      end
+      
+      def perform_with_block
+        @obj.__send__(@msg_id, *@argv) do |*x|
+          jump_error = nil
+          begin
+            block_value = block_yield(x)
+          rescue LocalJumpError
+            jump_error = $!
+          end
+          if jump_error
+            reason, jump_value = rescue_local_jump(jump_error)
+            case reason
+            when :retry
+              retry
+            when :break
+              break(jump_value)
+            else
+              raise jump_error
+            end
+          end
+          block_value
+        end
+      end
+    end
+  end
+end
diff --git a/lib/drb/observer.rb b/lib/drb/observer.rb
new file mode 100644
index 0000000000..e7f1668c52
--- /dev/null
+++ b/lib/drb/observer.rb
@@ -0,0 +1,22 @@
+require 'observer'
+
+module DRb
+  module DRbObservable
+    include Observable
+
+    def notify_observers(*arg)
+      if defined? @observer_state and @observer_state
+	if defined? @observer_peers
+	  for i in @observer_peers.dup
+	    begin
+	      i.update(*arg)
+	    rescue
+	      delete_observer(i)
+	    end
+	  end
+	end
+	@observer_state = false
+      end
+    end
+  end
+end
diff --git a/lib/drb/timeridconv.rb b/lib/drb/timeridconv.rb
new file mode 100644
index 0000000000..bb2c48d528
--- /dev/null
+++ b/lib/drb/timeridconv.rb
@@ -0,0 +1,91 @@
+require 'drb/drb'
+require 'monitor'
+
+module DRb
+  class TimerIdConv < DRbIdConv
+    class TimerHolder2
+      include MonitorMixin
+
+      class InvalidIndexError < RuntimeError; end
+
+      def initialize(timeout=600)
+	super()
+	@sentinel = Object.new
+	@gc = {}
+	@curr = {}
+	@renew = {}
+	@timeout = timeout
+	@keeper = keeper
+      end
+
+      def add(obj)
+	synchronize do 
+	  key = obj.__id__
+	  @curr[key] = obj
+	  return key
+	end
+      end
+
+      def fetch(key, dv=@sentinel)
+	synchronize do 
+	  obj = peek(key)
+	  if obj == @sentinel
+	    return dv unless dv == @sentinel
+	    raise InvalidIndexError
+	  end
+	  @renew[key] = obj # KeepIt
+	  return obj
+	end
+      end
+
+      def include?(key)
+	synchronize do 
+	  obj = peek(key)
+	  return false if obj == @sentinel
+	  true
+	end
+      end
+
+      def peek(key)
+	synchronize do 
+	  return @curr.fetch(key, @renew.fetch(key, @gc.fetch(key, @sentinel)))
+	end
+      end
+
+      private
+      def alternate
+	synchronize do
+	  @gc = @curr       # GCed
+	  @curr = @renew
+	  @renew = {}
+	end
+      end
+
+      def keeper
+	Thread.new do
+	  loop do
+	    size = alternate
+	    sleep(@timeout)
+	  end
+	end
+      end
+    end
+
+    def initialize(timeout=600)
+      @holder = TimerHolder2.new(timeout)
+    end
+
+    def to_obj(ref)
+      return super if ref.nil?
+      @holder.fetch(ref)
+    rescue TimerHolder2::InvalidIndexError
+      raise "invalid reference"
+    end
+
+    def to_id(obj)
+      return @holder.add(obj)
+    end
+  end
+end
+
+# DRb.install_id_conv(TimerIdConv.new)
diff --git a/lib/drb/unix.rb b/lib/drb/unix.rb
new file mode 100644
index 0000000000..f9a2f75acd
--- /dev/null
+++ b/lib/drb/unix.rb
@@ -0,0 +1,98 @@
+require 'socket'
+require 'drb/drb'
+
+module DRb
+
+  class DRbUNIXSocket < DRbTCPSocket
+    def self.parse_uri(uri)
+      if /^drbunix:(.*?)(\?(.*))?$/ =~ uri 
+	filename = $1
+	option = $3
+	[filename, option]
+      else
+	raise(DRbBadScheme, uri) unless uri =~ /^drbunix:/
+	raise(DRbBadURI, 'can\'t parse uri:' + uri)
+      end
+    end
+
+    def self.open(uri, config)
+      filename, option = parse_uri(uri)
+      filename.untaint
+      soc = UNIXSocket.open(filename)
+      self.new(uri, soc, config)
+    end
+
+    def self.open_server(uri, config)
+      filename, option = parse_uri(uri)
+      if filename.size == 0
+	soc = temp_server
+	uri = 'drbunix:' + soc.path
+      else
+	soc = UNIXServer.open(filename)
+      end
+      mode = config[:UNIXFileMode]
+      File.chmod(mode, filename) if mode
+
+      self.new(uri, soc, config, true)
+    end
+
+    def self.uri_option(uri, config)
+      filename, option = parse_uri(uri)
+      return "drbunix:#{filename}", option
+    end
+
+    def initialize(uri, soc, config={}, server_mode = false)
+      super(uri, soc, config)
+      set_sockopt(@socket)
+      @server_mode = server_mode
+      @acl = nil
+    end
+    
+    # import from tempfile.rb
+    Max_try = 10
+    private
+    def self.temp_server
+      tmpdir = ENV['TMPDIR'] || ENV['TMP'] || ENV['TEMP'] || '/tmp'
+      tmpdir = '/tmp' if $SAFE > 0 and tmpdir.tainted?
+      n = 0
+      while true
+	begin
+	  tmpname = sprintf('%s/druby%d.%d', tmpdir, $$, n)
+	  lock = tmpname + '.lock'
+	  unless File.exist?(tmpname) or File.exist?(lock)
+	    Dir.mkdir(lock)
+	    break
+	  end
+	rescue
+	  raise "cannot generate tempfile `%s'" % tmpname if n >= Max_try
+	  #sleep(1)
+	end
+	n += 1
+      end
+      soc = UNIXServer.new(tmpname)
+      Dir.rmdir(lock)
+      soc
+    end
+
+    public
+    def close
+      return unless @socket
+      path = @socket.path
+      @socket.close
+      File.unlink(path) if @server_mode
+      @socket = nil
+    end
+
+    def accept
+      s = @socket.accept
+      self.class.new(nil, s, @config)
+    end
+
+    def set_sockopt(soc)
+      soc.fcntl(Fcntl::F_SETFL, Fcntl::O_NONBLOCK) if defined? Fcntl::O_NONBLOCK
+      soc.fcntl(Fcntl::F_SETFL, Fcntl::FD_CLOEXEC) if defined? Fcntl::FD_CLOEXEC
+    end
+  end
+
+  DRbProtocol.add_protocol(DRbUNIXSocket)
+end