diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..8566567
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "shFlags"]
+	path = shFlags
+	url = git://github.com/nvie/shFlags.git
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a828d7e
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,59 @@
+#
+# Copyright 2010 Vincent Driessen. All rights reserved.
+# 
+# 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 VINCENT DRIESSEN ``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 VINCENT DRIESSEN 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.
+# 
+# The views and conclusions contained in the software and documentation are
+# those of the authors and should not be interpreted as representing official
+# policies, either expressed or implied, of Vincent Driessen.
+#
+
+# Determine if we're inside a debian build .. 
+ifdef DEB_BUILD_ARCH
+	prefix=$(DESTDIR)/usr/
+else
+	prefix=/usr/local
+endif
+
+# files that need mode 755
+EXEC_FILES=git-now
+
+# files that need mode 644
+SCRIPT_FILES =git-now-add
+SCRIPT_FILES+=git-now-grep
+SCRIPT_FILES+=git-now-rebase
+SCRIPT_FILES+=gitnow-common
+SCRIPT_FILES+=gitnow-shFlags
+
+all:
+	@echo "usage: make install"
+	@echo "       make uninstall"
+
+install:
+	install -d -m 0755 $(prefix)/bin
+	install -m 0755 $(EXEC_FILES) $(prefix)/bin
+	install -m 0644 $(SCRIPT_FILES) $(prefix)/bin
+
+uninstall:
+	test -d $(prefix)/bin && \
+		cd $(prefix)/bin && \
+		rm -f $(EXEC_FILES) $(SCRIPT_FILES)
diff --git a/.vimrc b/etc/.vimrc
similarity index 100%
rename from .vimrc
rename to etc/.vimrc
diff --git a/git-now.el b/etc/git-now.el
similarity index 100%
rename from git-now.el
rename to etc/git-now.el
diff --git a/git-now b/git-now
index bc1caf9..9ee7500 100755
--- a/git-now
+++ b/git-now
@@ -1,20 +1,75 @@
 #!/bin/sh
 
-PREFIX="from now"
-MESSAGE="[${PREFIX}] `date +\"%Y/%m/%d %T\"`"
-
-if [ $# -eq 0 ]
-then
-  git add -u
-  printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
-else
-then
-  if [ $1 != "--all" ]
-  then
-    git add $@
-  else
-    git add -u
-    git add .
-  fi
-  printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
+# enable debug mode
+if [ "$DEBUG" = "yes" ]; then
+  set -x
 fi
+
+export GITNOW_DIR=$(dirname "$0")
+PREFIX="from now"
+
+usage() {
+  echo "usage: git now [-n] [-v] [--force | -f] [--interactive | -i] [--patch | -p]"
+  echo "               [--edit | -e] [--all | [--update | -u]] [--intent-to-add | -N]"
+  echo "               [--refresh] [--ignore-errors] [--ignore-missing] [--]"
+  echo "               [<filepattern>...]"
+  echo
+  echo "       git now <subcommand>"
+  echo
+  echo "Available subcommands are:"
+  echo "   add       default subcommand."
+  echo "   rebase    rebase for temporary commits."
+  echo "   grep      grep temporary commits."
+  echo
+  echo "Try 'git now <subcommand> help' for details."
+}
+
+main() {
+  # load common functionality
+  . "$GITNOW_DIR/gitnow-common"
+
+  # This environmental variable fixes non-POSIX getopt style argument
+  # parsing, effectively breaking git-now subcommand parsing on several
+  # Linux platforms.
+  export POSIXLY_CORRECT=1
+
+  # use the shFlags project to parse the command line arguments
+  . "$GITNOW_DIR/gitnow-shFlags"
+
+  SUBCOMMAND="$1"
+  if [ ! -e "$GITNOW_DIR/git-now-$SUBCOMMAND" ]; then
+    if [ "$SUBCOMMAND" = "help" ]; then
+      usage
+      exit 0
+    else
+      SUBCOMMAND="add"
+    fi
+  else
+    FLAGS_PARENT="git now"
+    FLAGS "$@" || exit $?
+    eval set -- "${FLAGS_ARGV}"; shift
+
+    FLAGS_PARENT="git now $SUBCOMMAND"
+  fi
+
+  # run command
+  . "$GITNOW_DIR/git-now-$SUBCOMMAND"
+
+  # test if the first argument is a flag (i.e. starts with '-')
+  # in that case, we interpret this arg as a flag for the default
+  # command
+  SUBACTION="default"
+  if [ "$1" = "help" ] && { ! echo "$1" | grep -q "^-"; } then
+    SUBACTION="$1"; shift
+  fi
+  #if ! type "cmd_$SUBACTION" >/dev/null 2>&1; then
+  #warn "Unknown subcommand: '$SUBACTION'"
+  #usage
+  #exit 1
+  #fi
+
+  # run the specified action
+  cmd_$SUBACTION "$@"
+}
+
+main "$@"
diff --git a/git-now-add b/git-now-add
new file mode 100644
index 0000000..0976d63
--- /dev/null
+++ b/git-now-add
@@ -0,0 +1,28 @@
+usage() {
+  echo "usage: git now add [-n] [-v] [--force | -f] [--interactive | -i] [--patch | -p]"
+  echo "               [--edit | -e] [--all | [--update | -u]] [--intent-to-add | -N]"
+  echo "               [--refresh] [--ignore-errors] [--ignore-missing] [--]"
+  echo "               [<filepattern>...]"
+}
+
+cmd_default() {
+  MESSAGE="[${PREFIX}] `date +\"%Y/%m/%d %T\"`"
+  if [ $# -eq 0 ]; then
+    git add -u
+    printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
+  else
+    if [ $1 != "--all" ]; then
+      git add $@
+    else
+      git add -u
+      git add .
+    fi
+    printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
+  fi
+}
+
+cmd_help() {
+  usage
+  exit 0
+}
+
diff --git a/git-now-grep b/git-now-grep
new file mode 100644
index 0000000..d1d6e56
--- /dev/null
+++ b/git-now-grep
@@ -0,0 +1,29 @@
+usage() {
+  echo "usage: git now grep [<base_branch>]"
+}
+
+cmd_default() {
+  parse_args "$@"
+
+  if [ -n "$BASE_BRANCH" ]; then
+    WORKING_BRANCH=$(git_current_branch)
+    COMMON_ANCESTOR_COMMIT=`git merge-base ${BASE_BRANCH} ${WORKING_BRANCH}`
+    echo `git log ${COMMON_ANCESTOR_COMMIT}.. --pretty=oneline --grep="${PREFIX}"`
+  else
+    echo `git log --pretty=oneline --grep="${PREFIX}"`
+  fi
+}
+
+parse_args() {
+  # parse options
+  FLAGS "$@" || exit $?
+  eval set -- "${FLAGS_ARGV}"
+  # read arguments into global variables
+  BASE_BRANCH=$1
+}
+
+cmd_help() {
+  usage
+  exit 0
+}
+
diff --git a/git-now-rebase b/git-now-rebase
old mode 100755
new mode 100644
index 6376624..0d28509
--- a/git-now-rebase
+++ b/git-now-rebase
@@ -1,66 +1,67 @@
-#!/bin/sh
-
-usage_exit() {
-        echo "Usage: git now rebase [-h] [-p] [-r remote] [base_branch] " 1>&2
-        exit 1
+usage() {
+  echo "usage: git now rebase [<base_branch>]"
+  echo "       git now rebase --push|-p [--remote|-r <remote>] [<base_branch>]"
 }
-#
-# Options
-#
-while getopts "pr:h" GETOPTS
-do
-  case $GETOPTS in
-  p)    PUSH_FLAG=yes
-        ;;
-  r)    REMOTE_NAME=$OPTARG
-        ;;
-  h)    usage_exit
-        ;;
-  *)    usage_exit
-        ;;
-  esac
-done
 
-shift $((OPTIND - 1))
 
-PREFIX="from now"
-WORKING_BRANCH=`git branch -l | grep "*" | cut -d " " -f 2`
+cmd_default() {
+  parse_args "$@"
 
-if [ $# -eq 0 ]
-then
-  FIRST_NOW_COMMIT=`git log --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1`
-  INITIAL_COMMIT=`git log --pretty=oneline | tail -n 1 | cut -d " " -f 1`
+  WORKING_BRANCH=$(git_current_branch)
+  INITIAL_COMMIT=$(git_now_initial_commit)
 
-  if [ ${FIRST_NOW_COMMIT} != ${INITIAL_COMMIT} ]
-  then
-    echo "git rebase -i ${FIRST_NOW_COMMIT}^"
+  if [ -n "$BASE_BRANCH" ]; then
+    COMMON_ANCESTOR_COMMIT=`git merge-base ${BASE_BRANCH} ${WORKING_BRANCH}`
+    FIRST_NOW_COMMIT=$(git_now_first_commit $COMMON_ANCESTOR_COMMIT)
+
+    if [ "$FIRST_NOW_COMMIT" != "$INITIAL_COMMIT" ]; then
+      git rebase -i ${FIRST_NOW_COMMIT}^
+    else
+      git checkout ${FIRST_NOW_COMMIT}
+      git commit --amend
+      git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}
+    fi
   else
-    echo "git checkout ${FIRST_NOW_COMMIT}"
-    echo "git commit --amend"
-    echo "git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}"
+    FIRST_NOW_COMMIT=$(git_now_first_commit)
+
+    if [ "$FIRST_NOW_COMMIT" != "$INITIAL_COMMIT" ]; then
+      git rebase -i ${FIRST_NOW_COMMIT}^
+    else
+      git checkout ${FIRST_NOW_COMMIT}
+      git commit --amend
+      git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}
+    fi
   fi
-else
+
+  if flag push; then
+    _cmd_push $WORKING_BRANCH $REMOTE
+  fi
+}
+
+cmd_help() {
+  usage
+  exit 0
+}
+
+parse_args() {
+  # parse options
+  DEFINE_boolean 'push' false 'push to remote repository finally' 'p'
+  DEFINE_string 'remote' '' 'remote branch name to --set-upstream' 'r'
+  FLAGS "$@" || exit $?
+  eval set -- "${FLAGS_ARGV}"
+
+  # read arguments into global variables
   BASE_BRANCH=$1
-  COMMON_ANCESTOR_COMMIT=`git merge-base ${BASE_BRANCH} ${WORKING_BRANCH}`
-  FIRST_NOW_COMMIT=`git log ${COMMON_ANCESTOR_COMMIT}.. --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1`
-  INITIAL_COMMIT=`git log --pretty=oneline | tail -n 1 | cut -d " " -f 1`
+  REMOTE=$FLAGS_remote
+}
 
-  if [ ${FIRST_NOW_COMMIT} != ${INITIAL_COMMIT} ]
-  then
-    echo "git rebase -i ${FIRST_NOW_COMMIT}^"
+_cmd_push() {
+  local branch=$1
+  local remote=$2
+  if [ -n "$remote" ]; then
+    git push --set-upstream ${remote} ${branch}
   else
-    echo "git checkout ${FIRST_NOW_COMMIT}"
-    echo "git commit --amend"
-    echo "git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}"
+    git push
   fi
-fi
+}
 
-if [ $PUSH_FLAG ]
-then
-  if [ $REMOTE_NAME ]
-  then
-    echo "git push --set-upstream ${WORKING_BRANCH} ${REMOTE_NAME}/${WORKING_BRANCH}"
-  else
-    echo "git push"
-  fi
-fi
diff --git a/git-now.rb b/git-now.rb
index 2852ecd..d6f4229 100644
--- a/git-now.rb
+++ b/git-now.rb
@@ -1,7 +1,17 @@
 require 'formula'
 
-class GitNow < GithubGistFormula
-  url 'https://gist.github.com/raw/1167062/03c52077ce8c7fb72537bdf9cbd50bd11f3a9d5c/git-now'
-  md5 '72a36ca8deb21b7cc26b8a8f5dc3e7be'
-  homepage 'https://gist.github.com/1167062'
+class GitNow < Formula
+  url 'https://github.com/nvie/gitflow.git', :tag => 'v0.0.1'
+  version '0.0.1'
+  head 'https://github.com/iwata/git-now.git', :branch => 'develop'
+  homepage 'https://github.com/iwata/git-now'
+
+  # for longopt
+  depends_on 'gnu-getopt'
+
+  def install
+    system "make", "prefix=#{prefix}", "install"
+    system "brew ln gnu-getopt"
+  end
+
 end
diff --git a/gitnow-common b/gitnow-common
new file mode 100644
index 0000000..aec7aff
--- /dev/null
+++ b/gitnow-common
@@ -0,0 +1,52 @@
+#
+# Common functionality
+#
+
+# shell output
+warn() { echo "$@" >&2; }
+die() { warn "$@"; exit 1; }
+
+escape() {
+	echo "$1" | sed 's/\([\.\+\$\*]\)/\\\1/g'
+}
+
+# set logic
+has() {
+	local item=$1; shift
+	echo " $@ " | grep -q " $(escape $item) "
+}
+
+# basic math
+min() { [ "$1" -le "$2" ] && echo "$1" || echo "$2"; }
+max() { [ "$1" -ge "$2" ] && echo "$1" || echo "$2"; }
+
+# basic string matching
+startswith() { [ "$1" != "${1#$2}" ]; }
+endswith() { [ "$1" != "${1%$2}" ]; }
+
+# convenience functions for checking shFlags flags
+flag() { local FLAG; eval FLAG='$FLAGS_'$1; [ $FLAG -eq $FLAGS_TRUE ]; }
+noflag() { local FLAG; eval FLAG='$FLAGS_'$1; [ $FLAG -ne $FLAGS_TRUE ]; }
+
+#
+# Git specific common functionality
+#
+
+git_local_branches() { git branch --no-color | sed 's/^[* ] //'; }
+git_remote_branches() { git branch -r --no-color | sed 's/^[* ] //'; }
+git_all_branches() { ( git branch --no-color; git branch -r --no-color) | sed 's/^[* ] //'; }
+
+git_current_branch() {
+  git branch -l | grep "*" | cut -d " " -f 2
+}
+
+git_now_first_commit() {
+  local common=$1
+  if [ $# -eq 1 ]; then
+    git log ${common}.. --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1
+  else
+    git log --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1
+  fi
+}
+
+git_now_initial_commit() { git log --pretty=oneline | tail -n 1 | cut -d " " -f 1; }
diff --git a/gitnow-shFlags b/gitnow-shFlags
new file mode 120000
index 0000000..7b736c1
--- /dev/null
+++ b/gitnow-shFlags
@@ -0,0 +1 @@
+shFlags/src/shflags
\ No newline at end of file
diff --git a/shFlags b/shFlags
new file mode 160000
index 0000000..2fb06af
--- /dev/null
+++ b/shFlags
@@ -0,0 +1 @@
+Subproject commit 2fb06af13de884e9680f14a00c82e52a67c867f1
diff --git a/update b/update
deleted file mode 100644
index dd2d168..0000000
--- a/update
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/sh
-
-PREFIX="from now"
-
-if [ ! "`git log --pretty=oneline $3 | head -n 1 | grep "${PREFIX}"`" ]
-then
-    exit 0
-else
-    echo "error: There are tmp log messages in the received objects." 1>&2
-    echo "error: Change these messages by 'git now --rebase'." 1>&2
-    exit 1
-fi