diff --git a/.gitignore b/.gitignore
new file mode 100644
index 000000000..3ffde7df0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+Makefile
+gem_*
+gem-*
+mrb-*.a
+src/*.o
diff --git a/mrblib/dir.rb b/mrblib/dir.rb
new file mode 100644
index 000000000..b53a7102a
--- /dev/null
+++ b/mrblib/dir.rb
@@ -0,0 +1,49 @@
+class Dir
+  def each(&block)
+    while s = self.read
+      block.call(s)
+    end
+    self
+  end
+
+  alias pos tell
+  alias pos= seek
+
+  def self.entries(path)
+    a = []
+      self.open(path) { |d|
+      while s = d.read
+        a << s
+      end
+    }
+    a
+  end
+
+  def self.foreach(path, &block)
+    if block
+      self.open(path).each { |f| block.call(f) }
+    else
+      self.open(path).each
+    end
+  end
+
+  def self.open(path, &block)
+    if block
+      d = self.new(path)
+      begin
+        block.call(d)
+      ensure
+        d.close
+      end
+    else
+      self.new(path)
+    end
+  end
+
+  class << self
+    alias exists? exist?
+    alias pwd getwd
+    alias rmdir delete
+    alias unlink delete
+  end
+end
diff --git a/src/dir.c b/src/dir.c
new file mode 100644
index 000000000..e061817fa
--- /dev/null
+++ b/src/dir.c
@@ -0,0 +1,228 @@
+/*
+** dir.c - Dir
+**
+** See Copyright Notice in mruby.h
+*/
+
+#include "mruby.h"
+#include "mruby/class.h"
+#include "mruby/data.h"
+#include "mruby/string.h"
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+
+/* with/without IO module */
+#ifdef ENABLE_IO
+#include "mruby/ext/io.h"
+#else
+#define E_IO_ERROR E_RUNTIME_ERROR
+#endif
+
+struct mrb_dir {
+  DIR *dir;
+};
+
+void
+mrb_dir_free(mrb_state *mrb, void *ptr)
+{
+  struct mrb_dir *mdir = ptr;
+
+  if (mdir->dir) {
+    closedir(mdir->dir);
+    mdir->dir = NULL;
+  }
+  mrb_free(mrb, mdir);
+}
+
+static struct mrb_data_type mrb_dir_type = { "DIR", mrb_dir_free };
+
+mrb_value
+mrb_dir_close(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_dir *mdir;
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (!mdir) return mrb_nil_value();
+  if (!mdir->dir) {
+    mrb_raise(mrb, E_IO_ERROR, "closed directory");
+  }
+  if (closedir(mdir->dir) == -1) {
+    mrb_sys_fail(mrb, "closedir");
+  }
+  mdir->dir = NULL;
+  return mrb_nil_value();
+}
+
+mrb_value
+mrb_dir_init(mrb_state *mrb, mrb_value self)
+{
+  DIR *dir;
+  struct mrb_dir *mdir;
+  mrb_value path;
+  char *cpath;
+
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (mdir) {
+    mrb_dir_free(mrb, mdir);
+  }
+
+  mdir = (struct mrb_dir *)mrb_malloc(mrb, sizeof(*mdir));
+  mdir->dir = NULL;
+  DATA_PTR(self) = mdir;
+  DATA_TYPE(self) = &mrb_dir_type;
+
+  mrb_get_args(mrb, "S", &path);
+  cpath = mrb_str_to_cstr(mrb, path);
+  if ((dir = opendir(cpath)) == NULL) {
+    mrb_sys_fail(mrb, cpath);
+  }
+  mdir->dir = dir;
+  return self;
+}
+
+mrb_value
+mrb_dir_delete(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value path;
+  char *cpath;
+
+  mrb_get_args(mrb, "S", &path);
+  cpath = mrb_str_to_cstr(mrb, path);
+  if (rmdir(cpath) == -1) {
+    mrb_sys_fail(mrb, cpath);
+  }
+  return mrb_fixnum_value(0);
+}
+
+mrb_value
+mrb_dir_existp(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value path;
+  struct stat sb;
+  char *cpath;
+
+  mrb_get_args(mrb, "S", &path);
+  cpath = mrb_str_to_cstr(mrb, path);
+  if (stat(cpath, &sb) == 0 && S_ISDIR(sb.st_mode)) {
+    return mrb_true_value();
+  } else {
+    return mrb_false_value();
+  }
+}
+
+mrb_value
+mrb_dir_getwd(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value path;
+
+  path = mrb_str_buf_new(mrb, MAXPATHLEN);
+  if (getcwd(RSTRING_PTR(path), MAXPATHLEN) == NULL) {
+    mrb_sys_fail(mrb, "getcwd(2)");
+  }
+  mrb_str_resize(mrb, path, strlen(RSTRING_PTR(path)));
+  return path;
+}
+
+mrb_value
+mrb_dir_mkdir(mrb_state *mrb, mrb_value klass)
+{
+  mrb_int mode;
+  mrb_value spath;
+  char *path;
+
+  mode = 0777;
+  mrb_get_args(mrb, "S|i", &spath, &mode);
+  path = mrb_str_to_cstr(mrb, spath);
+  if (mkdir(path, mode) == -1) {
+    mrb_sys_fail(mrb, path);
+  }
+  return mrb_fixnum_value(0);
+}
+
+mrb_value
+mrb_dir_read(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_dir *mdir;
+  struct dirent *dp;
+
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (!mdir) return mrb_nil_value();
+  if (!mdir->dir) {
+    mrb_raise(mrb, E_IO_ERROR, "closed directory");
+  }
+  dp = readdir(mdir->dir);
+  if (dp != NULL) {
+    return mrb_str_new2(mrb, dp->d_name);
+  } else {
+    return mrb_nil_value();
+  }
+}
+
+mrb_value
+mrb_dir_rewind(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_dir *mdir;
+
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (!mdir) return mrb_nil_value();
+  if (!mdir->dir) {
+    mrb_raise(mrb, E_IO_ERROR, "closed directory");
+  }
+  rewinddir(mdir->dir);
+  return self;
+}
+
+mrb_value
+mrb_dir_seek(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_dir *mdir;
+  mrb_int pos;
+
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (!mdir) return mrb_nil_value();
+  if (!mdir->dir) {
+    mrb_raise(mrb, E_IO_ERROR, "closed directory");
+  }
+  mrb_get_args(mrb, "i", &pos);
+  seekdir(mdir->dir, (long)pos);
+  return self;
+}
+
+mrb_value
+mrb_dir_tell(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_dir *mdir;
+  mrb_int pos;
+
+  mdir = (struct mrb_dir *)mrb_get_datatype(mrb, self, &mrb_dir_type);
+  if (!mdir) return mrb_nil_value();
+  if (!mdir->dir) {
+    mrb_raise(mrb, E_IO_ERROR, "closed directory");
+  }
+  pos = (mrb_int)telldir(mdir->dir);
+  return mrb_fixnum_value(pos);
+}
+
+void
+mrb_mruby_dir_gem_init(mrb_state *mrb)
+{
+  struct RClass *d;
+
+  d = mrb_define_class(mrb, "Dir", mrb->object_class);
+  MRB_SET_INSTANCE_TT(d, MRB_TT_DATA);
+  mrb_define_class_method(mrb, d, "delete", mrb_dir_delete, ARGS_REQ(1));
+  mrb_define_class_method(mrb, d, "exist?", mrb_dir_existp, ARGS_REQ(1));
+  mrb_define_class_method(mrb, d, "getwd", mrb_dir_getwd, ARGS_NONE());
+  mrb_define_class_method(mrb, d, "mkdir", mrb_dir_mkdir, ARGS_REQ(1)|ARGS_OPT(1));
+  mrb_define_method(mrb, d, "close", mrb_dir_close, ARGS_NONE());
+  mrb_define_method(mrb, d, "initialize", mrb_dir_init, ARGS_REQ(1));
+  mrb_define_method(mrb, d, "read", mrb_dir_read, ARGS_NONE());
+  mrb_define_method(mrb, d, "rewind", mrb_dir_rewind, ARGS_NONE());
+  mrb_define_method(mrb, d, "seek", mrb_dir_seek, ARGS_REQ(1));
+  mrb_define_method(mrb, d, "tell", mrb_dir_tell, ARGS_NONE());
+}
diff --git a/test/dir.rb b/test/dir.rb
new file mode 100644
index 000000000..e69de29bb