diff -Naurd autoconf/ChangeLog autoconf-patched/ChangeLog
--- autoconf/ChangeLog	2006-09-06 12:58:50.000000000 +0900
+++ autoconf-patched/ChangeLog	2006-09-07 19:05:18.000000000 +0900
@@ -1,3 +1,11 @@
+2006-09-07  Romain Lenglet  <address@hidden>
+
+	* lib/autoconf/erlang.m4 (AC_ERLANG_SUBST_ERTS_VERSION): Added
+	AC_ERLANG_SUBST_ERTS_VERSION macro.
+	* doc/autoconf.texi (Erlang Libraries): Document
+	AC_ERLANG_SUBST_ERTS_VERSION macro and ERLANG_ERTS_VERSION
+	variable.
+
 2006-09-05  Paul Eggert  <address@hidden>
 
 	* doc/autoconf.texi (Preset Output Variables): srcdir and
diff -Naurd autoconf/doc/autoconf.texi autoconf-patched/doc/autoconf.texi
--- autoconf/doc/autoconf.texi	2006-09-06 12:58:50.000000000 +0900
+++ autoconf-patched/doc/autoconf.texi	2006-09-07 19:07:07.000000000 +0900
@@ -6724,7 +6724,7 @@
 @cindex Erlang
 
 Autoconf defines the following macros for determining paths to the essential
-Erlang/OTP programs:
+Erlang/OTP programs, and information about those programs:
 
 @defmac AC_ERLANG_PATH_ERLC (@ovar{value-if-not-found}, @ovar{path})
 @acindex{ERLANG_PATH_ERLC}
@@ -6755,9 +6755,10 @@
 @defmac AC_ERLANG_PATH_ERL (@ovar{value-if-not-found}, @ovar{path})
 @acindex{ERLANG_PATH_ERL}
 @ovindex ERL
-Determine an Erlang interpreter to use.  If @code{ERL} is not already set in the
-environment, check for @command{erl}.  Set output variable @code{ERL} to the
-complete path of the interpreter command found.
+Determine an Erlang interpreter (ERTS - Erlang RunTime System) to use.
+If @code{ERL} is not already set in the environment, check for
address@hidden  Set output variable @code{ERL} to the complete path of
+the interpreter command found.
 
 The two optional arguments have the same meaning as the two last arguments of
 macro @code{AC_PROG_PATH} for looking for the @command{erl} program.  For
@@ -6776,6 +6777,15 @@
 program is not found.
 @end defmac
 
address@hidden AC_ERLANG_SUBST_ERTS_VERSION
address@hidden
address@hidden ERLANG_ERTS_VERSION
+Determine the version of the Erlang interpreter (ERTS - Erlang RunTime
+System) that is run when running the command the @code{ERL} variable is
+set to.  Set output variable @code{ERLANG_ERTS_VERSION} to the version
+number of the interpreter.
address@hidden defmac
+
 
 @node Fortran Compiler
 @subsection Fortran Compiler Characteristics
@@ -7361,6 +7371,11 @@
 @end example
 @end defmac
 
+To determine the version of the Erlang emulator (ERTS - Erlang RunTime
+System), call the @code{AC_ERLANG_SUBST_ERTS_VERSION} macro instead,
+which substitutes the @code{ERLANG_ERTS_VERSION} variable with the
+emulator version.
+
 In addition to the above macros, which test installed Erlang libraries, the
 following macros determine the paths to the directories into which newly built
 Erlang libraries are to be installed:
diff -Naurd autoconf/lib/autoconf/erlang.m4 autoconf-patched/lib/autoconf/erlang.m4
--- autoconf/lib/autoconf/erlang.m4	2006-09-06 12:58:50.000000000 +0900
+++ autoconf-patched/lib/autoconf/erlang.m4	2006-09-07 18:40:59.000000000 +0900
@@ -269,6 +269,31 @@
 ])# AC_ERLANG_SUBST_LIB_DIR
 
 
+
+dnl Determines the version of the Erlang/OTP emulator (ERTS)
+
+# AC_ERLANG_SUBST_ERTS_VERSION
+# ---------------
+AC_DEFUN([AC_ERLANG_SUBST_ERTS_VERSION],
+[AC_REQUIRE([AC_ERLANG_NEED_ERLC])[]dnl
+AC_REQUIRE([AC_ERLANG_NEED_ERL])[]dnl
+AC_CACHE_CHECK([for the Erlang/OTP ERTS version],
+    [erlang_cv_erts_version],
+    [AC_LANG_PUSH(Erlang)[]dnl
+     AC_RUN_IFELSE(
+        [AC_LANG_PROGRAM([], [dnl
+            Version = erlang:system_info(version),
+            file:write_file("conftest.out", Version),
+            ReturnValue = 0,
+            halt(ReturnValue)])],
+        [erlang_cv_erts_version=`cat conftest.out`],
+        [AC_MSG_FAILURE([test Erlang program execution failed])])
+     AC_LANG_POP(Erlang)[]dnl
+    ])
+AC_SUBST([ERLANG_ERTS_VERSION], [$erlang_cv_erts_version])
+])# AC_ERLANG_SUBST_ERTS_VERSION
+
+
 dnl Directories for installing Erlang/OTP packages are separated from the
 dnl directories determined by running the Erlang/OTP installation that is used
 dnl for building.
diff -Naurd autoconf/NEWS autoconf-patched/NEWS
--- autoconf/NEWS	2006-09-02 14:37:07.000000000 +0900
+++ autoconf-patched/NEWS	2006-09-07 19:12:22.000000000 +0900
@@ -13,6 +13,12 @@
   New macro, with the behavior of the 2.60a AC_COMPUTE_INT macro.
   AC_COMPUTE_INT no longer caches or reports results.
 
+** New macros and substituted variables to support Erlang/OTP.
+  New variables substituted to versions of libraries, by the
+  AC_ERLANG_CHECK_LIB macro: ERLANG_LIB_VER_<lib>.
+  New macro to determine the version of the Erlang emulator (ERTS):
+  AC_ERLANG_SUBST_ERTS_VERSION.
+
 * Major changes in Autoconf 2.60a (2006-08-25)
 
 ** GNU M4 1.4.6 or later is now recommended.  At least one "make check"