diff --git a/aclocal/ax_lua.m4 b/aclocal/ax_lua.m4
new file mode 100644
index 0000000..1553491
--- /dev/null
+++ b/aclocal/ax_lua.m4
@@ -0,0 +1,663 @@
+# ===========================================================================
+#          http://www.gnu.org/software/autoconf-archive/ax_lua.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PROG_LUA[([MINIMUM-VERSION], [TOO-BIG-VERSION], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])]
+#   AX_LUA_HEADERS[([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])]
+#   AX_LUA_LIBS[([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])]
+#   AX_LUA_READLINE[([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])]
+#
+# DESCRIPTION
+#
+#   Detect a Lua interpreter, optionally specifying a minimum and maximum
+#   version number. Set up important Lua paths, such as the directories in
+#   which to install scripts and modules (shared libraries).
+#
+#   Also detect Lua headers and libraries. The Lua version contained in the
+#   header is checked to match the Lua interpreter version exactly. When
+#   searching for Lua libraries, the version number is used as a suffix.
+#   This is done with the goal of supporting multiple Lua installs (5.1 and
+#   5.2 side-by-side).
+#
+#   A note on compatibility with previous versions: This file has been
+#   mostly rewritten for serial 18. Most developers should be able to use
+#   these macros without needing to modify configure.ac. Care has been taken
+#   to preserve each macro's behavior, but there are some differences:
+#
+#   1) AX_WITH_LUA is deprecated; it now expands to the exact same thing as
+#   AX_PROG_LUA with no arguments.
+#
+#   2) AX_LUA_HEADERS now checks that the version number defined in lua.h
+#   matches the interpreter version. AX_LUA_HEADERS_VERSION is therefore
+#   unnecessary, so it is deprecated and does not expand to anything.
+#
+#   3) The configure flag --with-lua-suffix no longer exists; the user
+#   should instead specify the LUA precious variable on the command line.
+#   See the AX_PROG_LUA description for details.
+#
+#   Please read the macro descriptions below for more information.
+#
+#   This file was inspired by Andrew Dalke's and James Henstridge's
+#   python.m4 and Tom Payne's, Matthieu Moy's, and Reuben Thomas's ax_lua.m4
+#   (serial 17). Basically, this file is a mash-up of those two files. I
+#   like to think it combines the best of the two!
+#
+#   AX_PROG_LUA: Search for the Lua interpreter, and set up important Lua
+#   paths. Adds precious variable LUA, which may contain the path of the Lua
+#   interpreter. If LUA is blank, the user's path is searched for an
+#   suitable interpreter.
+#
+#   If MINIMUM-VERSION is supplied, then only Lua interpreters with a
+#   version number greater or equal to MINIMUM-VERSION will be accepted. If
+#   TOO-BIG- VERSION is also supplied, then only Lua interpreters with a
+#   version number greater or equal to MINIMUM-VERSION and less than
+#   TOO-BIG-VERSION will be accepted.
+#
+#   The Lua version number, LUA_VERSION, is found from the interpreter, and
+#   substituted. LUA_PLATFORM is also found, but not currently supported (no
+#   standard representation).
+#
+#   Finally, the macro finds four paths:
+#
+#     luadir             Directory to install Lua scripts.
+#     pkgluadir          $luadir/$PACKAGE
+#     luaexecdir         Directory to install Lua modules.
+#     pkgluaexecdir      $luaexecdir/$PACKAGE
+#
+#   These paths a found based on $prefix, $exec_prefix, Lua's package.path,
+#   and package.cpath. The first path of package.path beginning with $prefix
+#   is selected as luadir. The first path of package.cpath beginning with
+#   $exec_prefix is used as luaexecdir. This should work on all reasonable
+#   Lua installations. If a path cannot be determined, a default path is
+#   used. Of course, the user can override these later when invoking make.
+#
+#     luadir             Default: $prefix/share/lua/$LUA_VERSION
+#     luaexecdir         Default: $exec_prefix/lib/lua/$LUA_VERSION
+#
+#   These directories can be used by Automake as install destinations. The
+#   variable name minus 'dir' needs to be used as a prefix to the
+#   appropriate Automake primary, e.g. lua_SCRIPS or luaexec_LIBRARIES.
+#
+#   If an acceptable Lua interpreter is found, then ACTION-IF-FOUND is
+#   performed, otherwise ACTION-IF-NOT-FOUND is preformed. If ACTION-IF-NOT-
+#   FOUND is blank, then it will default to printing an error. To prevent
+#   the default behavior, give ':' as an action.
+#
+#   AX_LUA_HEADERS: Search for Lua headers. Requires that AX_PROG_LUA be
+#   expanded before this macro. Adds precious variable LUA_INCLUDE, which
+#   may contain Lua specific include flags, e.g. -I/usr/include/lua5.1. If
+#   LUA_INCLUDE is blank, then this macro will attempt to find suitable
+#   flags.
+#
+#   LUA_INCLUDE can be used by Automake to compile Lua modules or
+#   executables with embedded interpreters. The *_CPPFLAGS variables should
+#   be used for this purpose, e.g. myprog_CPPFLAGS = $(LUA_INCLUDE).
+#
+#   This macro searches for the header lua.h (and others). The search is
+#   performed with a combination of CPPFLAGS, CPATH, etc, and LUA_INCLUDE.
+#   If the search is unsuccessful, then some common directories are tried.
+#   If the headers are then found, then LUA_INCLUDE is set accordingly.
+#
+#   The paths automatically searched are:
+#
+#     * /usr/include/luaX.Y
+#     * /usr/include/lua/X.Y
+#     * /usr/include/luaXY
+#     * /usr/local/include/luaX.Y
+#     * /usr/local/include/lua-X.Y
+#     * /usr/local/include/lua/X.Y
+#     * /usr/local/include/luaXY
+#
+#   (Where X.Y is the Lua version number, e.g. 5.1.)
+#
+#   The Lua version number found in the headers is always checked to match
+#   the Lua interpreter's version number. Lua headers with mismatched
+#   version numbers are not accepted.
+#
+#   If headers are found, then ACTION-IF-FOUND is performed, otherwise
+#   ACTION-IF-NOT-FOUND is performed. If ACTION-IF-NOT-FOUND is blank, then
+#   it will default to printing an error. To prevent the default behavior,
+#   set the action to ':'.
+#
+#   AX_LUA_LIBS: Search for Lua libraries. Requires that AX_PROG_LUA be
+#   expanded before this macro. Adds precious variable LUA_LIB, which may
+#   contain Lua specific linker flags, e.g. -llua5.1. If LUA_LIB is blank,
+#   then this macro will attempt to find suitable flags.
+#
+#   LUA_LIB can be used by Automake to link Lua modules or executables with
+#   embedded interpreters. The *_LIBADD and *_LDADD variables should be used
+#   for this purpose, e.g. mymod_LIBADD = $(LUA_LIB).
+#
+#   This macro searches for the Lua library. More technically, it searches
+#   for a library containing the function lua_load. The search is performed
+#   with a combination of LIBS, LIBRARY_PATH, and LUA_LIB.
+#
+#   If the search determines that some linker flags are missing, then those
+#   flags will be added to LUA_LIB.
+#
+#   If libraries are found, then ACTION-IF-FOUND is performed, otherwise
+#   ACTION-IF-NOT-FOUND is performed. If ACTION-IF-NOT-FOUND is blank, then
+#   it will default to printing an error. To prevent the default behavior,
+#   set the action to ':'.
+#
+#   AX_LUA_READLINE: Search for readline headers and libraries. Requires the
+#   AX_LIB_READLINE macro, which is provided by ax_lib_readline.m4 from the
+#   Autoconf Archive.
+#
+#   If a readline compatible library is found, then ACTION-IF-FOUND is
+#   performed, otherwise ACTION-IF-NOT-FOUND is performed.
+#
+# LICENSE
+#
+#   Copyright (c) 2014 Reuben Thomas <rrt@sc3d.org>
+#   Copyright (c) 2014 Tim Perkins <tprk77@gmail.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 36
+
+dnl =========================================================================
+dnl AX_PROG_LUA([MINIMUM-VERSION], [TOO-BIG-VERSION],
+dnl             [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_PROG_LUA],
+[
+  dnl Check for required tools.
+  AC_REQUIRE([AC_PROG_GREP])
+  AC_REQUIRE([AC_PROG_SED])
+
+  dnl Make LUA a precious variable.
+  AC_ARG_VAR([LUA], [The Lua interpreter, e.g. /usr/bin/lua5.1])
+
+  dnl Find a Lua interpreter.
+  m4_define_default([_AX_LUA_INTERPRETER_LIST],
+    [lua lua5.2 lua52 lua5.1 lua51 lua50])
+
+  m4_if([$1], [],
+  [ dnl No version check is needed. Find any Lua interpreter.
+    AS_IF([test "x$LUA" = 'x'],
+      [AC_PATH_PROGS([LUA], [_AX_LUA_INTERPRETER_LIST], [:])])
+    ax_display_LUA='lua'
+
+    AS_IF([test "x$LUA" != 'x:'],
+      [ dnl At least check if this is a Lua interpreter.
+        AC_MSG_CHECKING([if $LUA is a Lua interpreter])
+        _AX_LUA_CHK_IS_INTRP([$LUA],
+          [AC_MSG_RESULT([yes])],
+          [ AC_MSG_RESULT([no])
+            AC_MSG_ERROR([not a Lua interpreter])
+          ])
+      ])
+  ],
+  [ dnl A version check is needed.
+    AS_IF([test "x$LUA" != 'x'],
+    [ dnl Check if this is a Lua interpreter.
+      AC_MSG_CHECKING([if $LUA is a Lua interpreter])
+      _AX_LUA_CHK_IS_INTRP([$LUA],
+        [AC_MSG_RESULT([yes])],
+        [ AC_MSG_RESULT([no])
+          AC_MSG_ERROR([not a Lua interpreter])
+        ])
+      dnl Check the version.
+      m4_if([$2], [],
+        [_ax_check_text="whether $LUA version >= $1"],
+        [_ax_check_text="whether $LUA version >= $1, < $2"])
+      AC_MSG_CHECKING([$_ax_check_text])
+      _AX_LUA_CHK_VER([$LUA], [$1], [$2],
+        [AC_MSG_RESULT([yes])],
+        [ AC_MSG_RESULT([no])
+          AC_MSG_ERROR([version is out of range for specified LUA])])
+      ax_display_LUA=$LUA
+    ],
+    [ dnl Try each interpreter until we find one that satisfies VERSION.
+      m4_if([$2], [],
+        [_ax_check_text="for a Lua interpreter with version >= $1"],
+        [_ax_check_text="for a Lua interpreter with version >= $1, < $2"])
+      AC_CACHE_CHECK([$_ax_check_text],
+        [ax_cv_pathless_LUA],
+        [ for ax_cv_pathless_LUA in _AX_LUA_INTERPRETER_LIST none; do
+            test "x$ax_cv_pathless_LUA" = 'xnone' && break
+            _AX_LUA_CHK_IS_INTRP([$ax_cv_pathless_LUA], [], [continue])
+            _AX_LUA_CHK_VER([$ax_cv_pathless_LUA], [$1], [$2], [break])
+          done
+        ])
+      dnl Set $LUA to the absolute path of $ax_cv_pathless_LUA.
+      AS_IF([test "x$ax_cv_pathless_LUA" = 'xnone'],
+        [LUA=':'],
+        [AC_PATH_PROG([LUA], [$ax_cv_pathless_LUA])])
+      ax_display_LUA=$ax_cv_pathless_LUA
+    ])
+  ])
+
+  AS_IF([test "x$LUA" = 'x:'],
+  [ dnl Run any user-specified action, or abort.
+    m4_default([$4], [AC_MSG_ERROR([cannot find suitable Lua interpreter])])
+  ],
+  [ dnl Query Lua for its version number.
+    AC_CACHE_CHECK([for $ax_display_LUA version],
+      [ax_cv_lua_version],
+      [ dnl Get the interpreter version in X.Y format. This should work for
+        dnl interpreters version 5.0 and beyond.
+        ax_cv_lua_version=[`$LUA -e '
+          -- return a version number in X.Y format
+          local _, _, ver = string.find(_VERSION, "^Lua (%d+%.%d+)")
+          print(ver)'`]
+      ])
+    AS_IF([test "x$ax_cv_lua_version" = 'x'],
+      [AC_MSG_ERROR([invalid Lua version number])])
+    AC_SUBST([LUA_VERSION], [$ax_cv_lua_version])
+    AC_SUBST([LUA_SHORT_VERSION], [`echo "$LUA_VERSION" | $SED 's|\.||'`])
+
+    dnl The following check is not supported:
+    dnl At times (like when building shared libraries) you may want to know
+    dnl which OS platform Lua thinks this is.
+    AC_CACHE_CHECK([for $ax_display_LUA platform],
+      [ax_cv_lua_platform],
+      [ax_cv_lua_platform=[`$LUA -e 'print("unknown")'`]])
+    AC_SUBST([LUA_PLATFORM], [$ax_cv_lua_platform])
+
+    dnl Use the values of $prefix and $exec_prefix for the corresponding
+    dnl values of LUA_PREFIX and LUA_EXEC_PREFIX. These are made distinct
+    dnl variables so they can be overridden if need be. However, the general
+    dnl consensus is that you shouldn't need this ability.
+    AC_SUBST([LUA_PREFIX], ['${prefix}'])
+    AC_SUBST([LUA_EXEC_PREFIX], ['${exec_prefix}'])
+
+    dnl Lua provides no way to query the script directory, and instead
+    dnl provides LUA_PATH. However, we should be able to make a safe educated
+    dnl guess. If the built-in search path contains a directory which is
+    dnl prefixed by $prefix, then we can store scripts there. The first
+    dnl matching path will be used.
+    AC_CACHE_CHECK([for $ax_display_LUA script directory],
+      [ax_cv_lua_luadir],
+      [ AS_IF([test "x$prefix" = 'xNONE'],
+          [ax_lua_prefix=$ac_default_prefix],
+          [ax_lua_prefix=$prefix])
+
+        dnl Initialize to the default path.
+        ax_cv_lua_luadir="$LUA_PREFIX/share/lua/$LUA_VERSION"
+
+        dnl Try to find a path with the prefix.
+        _AX_LUA_FND_PRFX_PTH([$LUA], [$ax_lua_prefix], [package.path])
+        AS_IF([test "x$ax_lua_prefixed_path" != 'x'],
+        [ dnl Fix the prefix.
+          _ax_strip_prefix=`echo "$ax_lua_prefix" | $SED 's|.|.|g'`
+          ax_cv_lua_luadir=`echo "$ax_lua_prefixed_path" | \
+            $SED "s|^$_ax_strip_prefix|$LUA_PREFIX|"`
+        ])
+      ])
+    AC_SUBST([luadir], [$ax_cv_lua_luadir])
+    AC_SUBST([pkgluadir], [\${luadir}/$PACKAGE])
+
+    dnl Lua provides no way to query the module directory, and instead
+    dnl provides LUA_PATH. However, we should be able to make a safe educated
+    dnl guess. If the built-in search path contains a directory which is
+    dnl prefixed by $exec_prefix, then we can store modules there. The first
+    dnl matching path will be used.
+    AC_CACHE_CHECK([for $ax_display_LUA module directory],
+      [ax_cv_lua_luaexecdir],
+      [ AS_IF([test "x$exec_prefix" = 'xNONE'],
+          [ax_lua_exec_prefix=$ax_lua_prefix],
+          [ax_lua_exec_prefix=$exec_prefix])
+
+        dnl Initialize to the default path.
+        ax_cv_lua_luaexecdir="$LUA_EXEC_PREFIX/lib/lua/$LUA_VERSION"
+
+        dnl Try to find a path with the prefix.
+        _AX_LUA_FND_PRFX_PTH([$LUA],
+          [$ax_lua_exec_prefix], [package.cpath])
+        AS_IF([test "x$ax_lua_prefixed_path" != 'x'],
+        [ dnl Fix the prefix.
+          _ax_strip_prefix=`echo "$ax_lua_exec_prefix" | $SED 's|.|.|g'`
+          ax_cv_lua_luaexecdir=`echo "$ax_lua_prefixed_path" | \
+            $SED "s|^$_ax_strip_prefix|$LUA_EXEC_PREFIX|"`
+        ])
+      ])
+    AC_SUBST([luaexecdir], [$ax_cv_lua_luaexecdir])
+    AC_SUBST([pkgluaexecdir], [\${luaexecdir}/$PACKAGE])
+
+    dnl Run any user specified action.
+    $3
+  ])
+])
+
+dnl AX_WITH_LUA is now the same thing as AX_PROG_LUA.
+AC_DEFUN([AX_WITH_LUA],
+[
+  AC_MSG_WARN([[$0 is deprecated, please use AX_PROG_LUA instead]])
+  AX_PROG_LUA
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_CHK_IS_INTRP(PROG, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_CHK_IS_INTRP],
+[
+  dnl A minimal Lua factorial to prove this is an interpreter. This should work
+  dnl for Lua interpreters version 5.0 and beyond.
+  _ax_lua_factorial=[`$1 2>/dev/null -e '
+    -- a simple factorial
+    function fact (n)
+      if n == 0 then
+        return 1
+      else
+        return n * fact(n-1)
+      end
+    end
+    print("fact(5) is " .. fact(5))'`]
+  AS_IF([test "$_ax_lua_factorial" = 'fact(5) is 120'],
+    [$2], [$3])
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_CHK_VER(PROG, MINIMUM-VERSION, [TOO-BIG-VERSION],
+dnl                 [ACTION-IF-TRUE], [ACTION-IF-FALSE])
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_CHK_VER],
+[
+  dnl Check that the Lua version is within the bounds. Only the major and minor
+  dnl version numbers are considered. This should work for Lua interpreters
+  dnl version 5.0 and beyond.
+  _ax_lua_good_version=[`$1 -e '
+    -- a script to compare versions
+    function verstr2num(verstr)
+      local _, _, majorver, minorver = string.find(verstr, "^(%d+)%.(%d+)")
+      if majorver and minorver then
+        return tonumber(majorver) * 100 + tonumber(minorver)
+      end
+    end
+    local minver = verstr2num("$2")
+    local _, _, trimver = string.find(_VERSION, "^Lua (.*)")
+    local ver = verstr2num(trimver)
+    local maxver = verstr2num("$3") or 1e9
+    if minver <= ver and ver < maxver then
+      print("yes")
+    else
+      print("no")
+    end'`]
+    AS_IF([test "x$_ax_lua_good_version" = "xyes"],
+      [$4], [$5])
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_FND_PRFX_PTH(PROG, PREFIX, SCRIPT-OR-MODULE-DIR)
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_FND_PRFX_PTH],
+[
+  dnl Get the script or module directory by querying the Lua interpreter,
+  dnl filtering on the given prefix, and selecting the shallowest path. If no
+  dnl path  is found matching the prefix, the result will be an empty string.
+  dnl The third argument determines the type of search, it can be 'script' or
+  dnl 'module'. Supplying 'script' will perform the search with package.path
+  dnl and LUA_PATH, and supplying 'module' will search with package.cpath and
+  dnl LUA_CPATH. This is done for compatibility with Lua 5.0.
+
+  ax_lua_prefixed_path=[`$1 -e '
+    -- get the path based on search type
+    local searchtype = "$3"
+    local paths = ""
+    if searchtype == "script" then
+      paths = (package and package.path) or LUA_PATH
+    elseif searchtype == "module" then
+      paths = (package and package.cpath) or LUA_CPATH
+    end
+    -- search for the prefix
+    local prefix = "$2"
+    local minpath = ""
+    local mindepth = 1e9
+    string.gsub(paths, "(@<:@^;@:>@+)",
+      function (path)
+        path = string.gsub(path, "%?.*$", "")
+        path = string.gsub(path, "/@<:@^/@:>@*$", "")
+        if string.find(path, prefix) then
+          local depth = string.len(string.gsub(path, "@<:@^/@:>@", ""))
+          if depth < mindepth then
+            minpath = path
+            mindepth = depth
+          end
+        end
+      end)
+    print(minpath)'`]
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_HEADERS([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_HEADERS],
+[
+  dnl Check for LUA_VERSION.
+  AC_MSG_CHECKING([if LUA_VERSION is defined])
+  AS_IF([test "x$LUA_VERSION" != 'x'],
+    [AC_MSG_RESULT([yes])],
+    [ AC_MSG_RESULT([no])
+      AC_MSG_ERROR([cannot check Lua headers without knowing LUA_VERSION])
+    ])
+
+  dnl Make LUA_INCLUDE a precious variable.
+  AC_ARG_VAR([LUA_INCLUDE], [The Lua includes, e.g. -I/usr/include/lua5.1])
+
+  dnl Some default directories to search.
+  LUA_SHORT_VERSION=`echo "$LUA_VERSION" | $SED 's|\.||'`
+  m4_define_default([_AX_LUA_INCLUDE_LIST],
+    [ /usr/include/lua$LUA_VERSION \
+      /usr/include/lua-$LUA_VERSION \
+      /usr/include/lua/$LUA_VERSION \
+      /usr/include/lua$LUA_SHORT_VERSION \
+      /usr/local/include/lua$LUA_VERSION \
+      /usr/local/include/lua-$LUA_VERSION \
+      /usr/local/include/lua/$LUA_VERSION \
+      /usr/local/include/lua$LUA_SHORT_VERSION \
+    ])
+
+  dnl Try to find the headers.
+  _ax_lua_saved_cppflags=$CPPFLAGS
+  CPPFLAGS="$CPPFLAGS $LUA_INCLUDE"
+  AC_CHECK_HEADERS([lua.h lualib.h lauxlib.h luaconf.h])
+  CPPFLAGS=$_ax_lua_saved_cppflags
+
+  dnl Try some other directories if LUA_INCLUDE was not set.
+  AS_IF([test "x$LUA_INCLUDE" = 'x' &&
+         test "x$ac_cv_header_lua_h" != 'xyes'],
+    [ dnl Try some common include paths.
+      for _ax_include_path in _AX_LUA_INCLUDE_LIST; do
+        test ! -d "$_ax_include_path" && continue
+
+        AC_MSG_CHECKING([for Lua headers in])
+        AC_MSG_RESULT([$_ax_include_path])
+
+        AS_UNSET([ac_cv_header_lua_h])
+        AS_UNSET([ac_cv_header_lualib_h])
+        AS_UNSET([ac_cv_header_lauxlib_h])
+        AS_UNSET([ac_cv_header_luaconf_h])
+
+        _ax_lua_saved_cppflags=$CPPFLAGS
+        CPPFLAGS="$CPPFLAGS -I$_ax_include_path"
+        AC_CHECK_HEADERS([lua.h lualib.h lauxlib.h luaconf.h])
+        CPPFLAGS=$_ax_lua_saved_cppflags
+
+        AS_IF([test "x$ac_cv_header_lua_h" = 'xyes'],
+          [ LUA_INCLUDE="-I$_ax_include_path"
+            break
+          ])
+      done
+    ])
+
+  AS_IF([test "x$ac_cv_header_lua_h" = 'xyes'],
+    [ dnl Make a program to print LUA_VERSION defined in the header.
+      dnl TODO It would be really nice if we could do this without compiling a
+      dnl program, then it would work when cross compiling. But I'm not sure how
+      dnl to do this reliably. For now, assume versions match when cross compiling.
+
+      AS_IF([test "x$cross_compiling" != 'xyes'],
+        [ AC_CACHE_CHECK([for Lua header version],
+            [ax_cv_lua_header_version],
+            [ _ax_lua_saved_cppflags=$CPPFLAGS
+              CPPFLAGS="$CPPFLAGS $LUA_INCLUDE"
+              AC_RUN_IFELSE(
+                [ AC_LANG_SOURCE([[
+#include <lua.h>
+#include <stdlib.h>
+#include <stdio.h>
+int main(int argc, char ** argv)
+{
+  if(argc > 1) printf("%s", LUA_VERSION);
+  exit(EXIT_SUCCESS);
+}
+]])
+                ],
+                [ ax_cv_lua_header_version=`./conftest$EXEEXT p | \
+                    $SED -n "s|^Lua \(@<:@0-9@:>@\{1,\}\.@<:@0-9@:>@\{1,\}\).\{0,\}|\1|p"`
+                ],
+                [ax_cv_lua_header_version='unknown'])
+              CPPFLAGS=$_ax_lua_saved_cppflags
+            ])
+
+          dnl Compare this to the previously found LUA_VERSION.
+          AC_MSG_CHECKING([if Lua header version matches $LUA_VERSION])
+          AS_IF([test "x$ax_cv_lua_header_version" = "x$LUA_VERSION"],
+            [ AC_MSG_RESULT([yes])
+              ax_header_version_match='yes'
+            ],
+            [ AC_MSG_RESULT([no])
+              ax_header_version_match='no'
+            ])
+        ],
+        [ AC_MSG_WARN([cross compiling so assuming header version number matches])
+          ax_header_version_match='yes'
+        ])
+    ])
+
+  dnl Was LUA_INCLUDE specified?
+  AS_IF([test "x$ax_header_version_match" != 'xyes' &&
+         test "x$LUA_INCLUDE" != 'x'],
+    [AC_MSG_ERROR([cannot find headers for specified LUA_INCLUDE])])
+
+  dnl Test the final result and run user code.
+  AS_IF([test "x$ax_header_version_match" = 'xyes'], [$1],
+    [m4_default([$2], [AC_MSG_ERROR([cannot find Lua includes])])])
+])
+
+dnl AX_LUA_HEADERS_VERSION no longer exists, use AX_LUA_HEADERS.
+AC_DEFUN([AX_LUA_HEADERS_VERSION],
+[
+  AC_MSG_WARN([[$0 is deprecated, please use AX_LUA_HEADERS instead]])
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_LIBS([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_LIBS],
+[
+  dnl TODO Should this macro also check various -L flags?
+
+  dnl Check for LUA_VERSION.
+  AC_MSG_CHECKING([if LUA_VERSION is defined])
+  AS_IF([test "x$LUA_VERSION" != 'x'],
+    [AC_MSG_RESULT([yes])],
+    [ AC_MSG_RESULT([no])
+      AC_MSG_ERROR([cannot check Lua libs without knowing LUA_VERSION])
+    ])
+
+  dnl Make LUA_LIB a precious variable.
+  AC_ARG_VAR([LUA_LIB], [The Lua library, e.g. -llua5.1])
+
+  AS_IF([test "x$LUA_LIB" != 'x'],
+  [ dnl Check that LUA_LIBS works.
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([lua_load], [],
+      [_ax_found_lua_libs='yes'],
+      [_ax_found_lua_libs='no'])
+    LIBS=$_ax_lua_saved_libs
+
+    dnl Check the result.
+    AS_IF([test "x$_ax_found_lua_libs" != 'xyes'],
+      [AC_MSG_ERROR([cannot find libs for specified LUA_LIB])])
+  ],
+  [ dnl First search for extra libs.
+    _ax_lua_extra_libs=''
+
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([exp], [m])
+    AC_SEARCH_LIBS([dlopen], [dl])
+    LIBS=$_ax_lua_saved_libs
+
+    AS_IF([test "x$ac_cv_search_exp" != 'xno' &&
+           test "x$ac_cv_search_exp" != 'xnone required'],
+      [_ax_lua_extra_libs="$_ax_lua_extra_libs $ac_cv_search_exp"])
+
+    AS_IF([test "x$ac_cv_search_dlopen" != 'xno' &&
+           test "x$ac_cv_search_dlopen" != 'xnone required'],
+      [_ax_lua_extra_libs="$_ax_lua_extra_libs $ac_cv_search_dlopen"])
+
+    dnl Try to find the Lua libs.
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([lua_load],
+      [ lua$LUA_VERSION \
+        lua$LUA_SHORT_VERSION \
+        lua-$LUA_VERSION \
+        lua-$LUA_SHORT_VERSION \
+        lua \
+      ],
+      [_ax_found_lua_libs='yes'],
+      [_ax_found_lua_libs='no'],
+      [$_ax_lua_extra_libs])
+    LIBS=$_ax_lua_saved_libs
+
+    AS_IF([test "x$ac_cv_search_lua_load" != 'xno' &&
+           test "x$ac_cv_search_lua_load" != 'xnone required'],
+      [LUA_LIB="$ac_cv_search_lua_load $_ax_lua_extra_libs"])
+  ])
+
+  dnl Test the result and run user code.
+  AS_IF([test "x$_ax_found_lua_libs" = 'xyes'], [$1],
+    [m4_default([$2], [AC_MSG_ERROR([cannot find Lua libs])])])
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_READLINE([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_READLINE],
+[
+  AX_LIB_READLINE
+  AS_IF([test "x$ac_cv_header_readline_readline_h" != 'x' &&
+         test "x$ac_cv_header_readline_history_h" != 'x'],
+    [ LUA_LIBS_CFLAGS="-DLUA_USE_READLINE $LUA_LIBS_CFLAGS"
+      $1
+    ],
+    [$2])
+])
diff --git a/configure.ac b/configure.ac
index 54eb1e4..44d7d6e 100755
--- a/configure.ac
+++ b/configure.ac
@@ -246,9 +246,10 @@
 AX_THRIFT_LIB(lua, [Lua], yes)
 have_lua=no
 if test "$with_lua" = "yes"; then
-  AC_PATH_PROGS([LUA], [lua])
-  if test "x$LUA" != "x"; then
-    have_lua="yes"
+  AX_PROG_LUA(5.2,, have_lua="yes", have_lua="no")
+  if test "$have_lua" = "yes"; then
+    AX_LUA_HEADERS(, have_lua="no")
+    AX_LUA_LIBS(, have_lua="no")
   fi
 fi
 AM_CONDITIONAL(WITH_LUA, [test "$have_lua" = "yes"])
diff --git a/lib/lua/Makefile.am b/lib/lua/Makefile.am
index 16170d4..896ff30 100644
--- a/lib/lua/Makefile.am
+++ b/lib/lua/Makefile.am
@@ -34,25 +34,25 @@
 nobase_include_HEADERS = src/socket.h
 
 libluasocket_la_CPPFLAGS = $(AM_CPPFLAGS) -I/usr/include/lua5.2 -DLUA_COMPAT_MODULE
-libluasocket_la_LDFLAGS = $(AM_LDFLAGS) -llua5.2 -lm
+libluasocket_la_LDFLAGS = $(AM_LDFLAGS) $(LUA_LIB) -lm
 
 libluabpack_la_SOURCES = src/luabpack.c
 
 libluabpack_la_CPPFLAGS = $(AM_CPPFLAGS) -I/usr/include/lua5.2 -DLUA_COMPAT_MODULE
-libluabpack_la_LDFLAGS = $(AM_LDFLAGS) -llua5.2 -lm
+libluabpack_la_LDFLAGS = $(AM_LDFLAGS) $(LUA_LIB) -lm
 libluabpack_la_LIBADD = liblualongnumber.la
 
 libluabitwise_la_SOURCES = src/luabitwise.c
 
 libluabitwise_la_CPPFLAGS = $(AM_CPPFLAGS) -I/usr/include/lua5.2 -DLUA_COMPAT_MODULE
-libluabitwise_la_LDFLAGS = $(AM_LDFLAGS) -llua5.2 -lm
+libluabitwise_la_LDFLAGS = $(AM_LDFLAGS) $(LUA_LIB) -lm
 
 liblualongnumber_la_SOURCES = \
 		src/lualongnumber.c \
 		src/longnumberutils.c
 
 liblualongnumber_la_CPPFLAGS = $(AM_CPPFLAGS) -I/usr/include/lua5.2 -DLUA_COMPAT_MODULE
-liblualongnumber_la_LDFLAGS = $(AM_LDFLAGS) -llua5.2 -lm
+liblualongnumber_la_LDFLAGS = $(AM_LDFLAGS) $(LUA_LIB) -lm
 
 EXTRA_DIST = TBinaryProtocol.lua \
 		TBufferedTransport.lua \