diff --git a/configure.ac b/configure.ac
index e1b1932..a7d5085 100755
--- a/configure.ac
+++ b/configure.ac
@@ -308,19 +308,54 @@ AM_COND_IF([AWS4C_DIR],[
 ])
 
 
-# Amazon S3 support  [see also:  --with-aws4c]
-AC_ARG_WITH([S3],
-        [AS_HELP_STRING([--with-S3],
-           [support IO with Amazon S3 backend @<:@default=no@:>@])],
+
+# Amazon S3 support using the libs3 API
+AC_ARG_WITH([S3-libs3],
+        [AS_HELP_STRING([--with-S3-libs3],
+           [support IO with Amazon libS3 @<:@default=no@:>@])],
         [],
-        [with_S3=no])
-AM_CONDITIONAL([USE_S3_AIORI], [test x$with_S3 = xyes])
-AM_COND_IF([USE_S3_AIORI],[
-        AC_DEFINE([USE_S3_AIORI], [], [Build Amazon-S3 backend AIORI])
+        [with_S3_libs3=no])
+AM_CONDITIONAL([USE_S3_LIBS3_AIORI], [test x$with_S3_libs3 = xyes])
+AM_COND_IF([USE_S3_LIBS3_AIORI],[
+        AC_DEFINE([USE_S3_LIBS3_AIORI], [], [Build Amazon-S3 backend AIORI using libs3])
 ])
 
 err=0
-AS_IF([test "x$with_S3" != xno], [
+AS_IF([test "x$with_S3_libs3" != xno], [
+            AC_MSG_NOTICE([beginning of S3-related checks])
+            ORIG_CPPFLAGS=$CPPFLAGS
+            ORIG_LDFLAGS=$LDFLAGS
+
+            AC_CHECK_HEADERS([libs3.h], [], [err=1])
+
+            # Autotools thinks searching for a library means I want it added to LIBS
+            ORIG_LIBS=$LIBS
+            AC_CHECK_LIB([s3], [S3_initialize], [], [err=1])
+            LIBS=$ORIG_LIBS
+
+            AC_MSG_NOTICE([end of S3-related checks])
+            if test "$err" == 1; then
+                AC_MSG_FAILURE([S3 support is missing.  dnl Make sure you have access to libs3.  dnl])
+            fi
+
+            # restore user's values
+            CPPFLAGS=$ORIG_CPPFLAGS
+            LDFLAGS=$ORIG_LDFLAGS
+])
+
+# Amazon S3 support  [see also:  --with-aws4c]
+AC_ARG_WITH([S3-4c],
+        [AS_HELP_STRING([--with-S3-4c],
+           [support IO with Amazon S3 backend @<:@default=no@:>@])],
+        [],
+        [with_S3_4c=no])
+AM_CONDITIONAL([USE_S3_4C_AIORI], [test x$with_S3_4c = xyes])
+AM_COND_IF([USE_S3_4C_AIORI],[
+        AC_DEFINE([USE_S3_4C_AIORI], [], [Build Amazon-S3 backend AIORI using lib4c])
+])
+
+err=0
+AS_IF([test "x$with_S3_4c" != xno], [
             AC_MSG_NOTICE([beginning of S3-related checks])
 
             # save user's values, while we use AC_CHECK_HEADERS with $AWS4C_DIR
diff --git a/src/Makefile.am b/src/Makefile.am
index 7cbd448..c718169 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -90,8 +90,8 @@ extraSOURCES += aiori-Gfarm.c
 extraLDADD += -lgfarm
 endif
 
-if USE_S3_AIORI
-extraSOURCES  += aiori-S3.c
+if USE_S3_4C_AIORI
+extraSOURCES  += aiori-S3-4c.c
 if AWS4C_DIR
   extraCPPFLAGS += $(AWS4C_CPPFLAGS)
   extraLDFLAGS  += $(AWS4C_LDFLAGS)
@@ -102,6 +102,11 @@ extraLDADD    += -laws4c
 extraLDADD    += -laws4c_extra
 endif
 
+if USE_S3_LIBS3_AIORI
+extraSOURCES  += aiori-S3-libs3.c
+extraLDADD    += -ls3
+endif
+
 if WITH_LUSTRE
 extraLDADD  += -llustreapi
 endif
diff --git a/src/aiori-S3.c b/src/aiori-S3-4c.c
similarity index 99%
rename from src/aiori-S3.c
rename to src/aiori-S3-4c.c
index 3999739..a1465b7 100755
--- a/src/aiori-S3.c
+++ b/src/aiori-S3-4c.c
@@ -130,7 +130,7 @@ const char* bucket_name = "ior";
 #   define      IOR_CURL_NOCONTINUE  0x02
 #   define      IOR_CURL_S3_EMC_EXT  0x04 /* allow EMC extensions to S3? */
 
-#ifdef USE_S3_AIORI
+#ifdef USE_S3_4C_AIORI
 #  include <curl/curl.h>
 #  include "aws4c.h"
 #else
@@ -167,8 +167,8 @@ static int S3_check_params(IOR_param_t *);
 // "Pure S3"
 //     N:1 writes use multi-part upload
 //     N:N fails if "transfer-size" != "block-size" (because that requires "append")
-ior_aiori_t s3_aiori = {
-	.name = "S3",
+ior_aiori_t s3_4c_aiori = {
+	.name = "S3-4c",
 	.name_legacy = NULL,
 	.create = S3_Create,
 	.open = S3_Open,
diff --git a/src/aiori-S3-libs3.c b/src/aiori-S3-libs3.c
new file mode 100644
index 0000000..5c9129f
--- /dev/null
+++ b/src/aiori-S3-libs3.c
@@ -0,0 +1,199 @@
+/*
+* S3 implementation using the newer libs3
+*/
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "ior.h"
+#include "aiori.h"
+#include "utilities.h"
+
+
+/************************** O P T I O N S *****************************/
+typedef struct {
+  uint64_t delay_creates;
+  uint64_t delay_xfer;
+  int delay_rank_0_only;
+} dummy_options_t;
+
+static char * current = (char*) 1;
+
+static option_help * S3_options(aiori_mod_opt_t ** init_backend_options, aiori_mod_opt_t * init_values){
+  dummy_options_t * o = malloc(sizeof(dummy_options_t));
+  if (init_values != NULL){
+    memcpy(o, init_values, sizeof(dummy_options_t));
+  }else{
+    memset(o, 0, sizeof(dummy_options_t));
+  }
+
+  *init_backend_options = (aiori_mod_opt_t*) o;
+
+  option_help h [] = {
+      {0, "dummy.delay-create",        "Delay per create in usec", OPTION_OPTIONAL_ARGUMENT, 'l', & o->delay_creates},
+      {0, "dummy.delay-xfer",          "Delay per xfer in usec", OPTION_OPTIONAL_ARGUMENT, 'l', & o->delay_xfer},
+      {0, "dummy.delay-only-rank0",    "Delay only Rank0", OPTION_FLAG, 'd', & o->delay_rank_0_only},
+      LAST_OPTION
+  };
+  option_help * help = malloc(sizeof(h));
+  memcpy(help, h, sizeof(h));
+  return help;
+}
+
+static int count_init = 0;
+
+static aiori_fd_t *S3_Create(char *testFileName, int iorflags, aiori_mod_opt_t * options)
+{
+  if(count_init <= 0){
+    ERR("S3 missing initialization in create\n");
+  }
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 create: %s = %p\n", testFileName, current);
+  }
+  dummy_options_t * o = (dummy_options_t*) options;
+  if (o->delay_creates){
+    if (! o->delay_rank_0_only || (o->delay_rank_0_only && rank == 0)){
+      struct timespec wait = { o->delay_creates / 1000 / 1000, 1000l * (o->delay_creates % 1000000)};
+      nanosleep( & wait, NULL);
+    }
+  }
+  return (aiori_fd_t*) current++;
+}
+
+static aiori_fd_t *S3_Open(char *testFileName, int flags, aiori_mod_opt_t * options)
+{
+  if(count_init <= 0){
+    ERR("S3 missing initialization in open\n");
+  }
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 open: %s = %p\n", testFileName, current);
+  }
+  return (aiori_fd_t*) current++;
+}
+
+static void S3_Fsync(aiori_fd_t *fd, aiori_mod_opt_t * options)
+{
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 fsync %p\n", fd);
+  }
+}
+
+
+static void S3_Sync(aiori_mod_opt_t * options)
+{
+}
+
+static void S3_Close(aiori_fd_t *fd, aiori_mod_opt_t * options)
+{
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 close %p\n", fd);
+  }
+}
+
+static void S3_Delete(char *testFileName, aiori_mod_opt_t * options)
+{
+    if(verbose > 4){
+      fprintf(out_logfile, "S3 delete: %s\n", testFileName);
+    }
+}
+
+static char * S3_getVersion()
+{
+  return "0.5";
+}
+
+static IOR_offset_t S3_GetFileSize(aiori_mod_opt_t * options, char *testFileName)
+{
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 getFileSize: %s\n", testFileName);
+  }
+  return 0;
+}
+
+static IOR_offset_t S3_Xfer(int access, aiori_fd_t *file, IOR_size_t * buffer, IOR_offset_t length, IOR_offset_t offset, aiori_mod_opt_t * options){
+  if(verbose > 4){
+    fprintf(out_logfile, "S3 xfer: %p\n", file);
+  }
+  dummy_options_t * o = (dummy_options_t*) options;
+  if (o->delay_xfer){
+    if (! o->delay_rank_0_only || (o->delay_rank_0_only && rank == 0)){
+      struct timespec wait = {o->delay_xfer / 1000 / 1000, 1000l * (o->delay_xfer % 1000000)};
+      nanosleep( & wait, NULL);
+    }
+  }
+  return length;
+}
+
+static int S3_statfs (const char * path, ior_aiori_statfs_t * stat, aiori_mod_opt_t * options){
+  stat->f_bsize = 1;
+  stat->f_blocks = 1;
+  stat->f_bfree = 1;
+  stat->f_bavail = 1;
+  stat->f_files = 1;
+  stat->f_ffree = 1;
+  return 0;
+}
+
+static int S3_mkdir (const char *path, mode_t mode, aiori_mod_opt_t * options){
+  return 0;
+}
+
+static int S3_rmdir (const char *path, aiori_mod_opt_t * options){
+  return 0;
+}
+
+static int S3_access (const char *path, int mode, aiori_mod_opt_t * options){
+  return 0;
+}
+
+static int S3_stat (const char *path, struct stat *buf, aiori_mod_opt_t * options){
+  return 0;
+}
+
+static int S3_check_params(aiori_mod_opt_t * options){
+  return 0;
+}
+
+static void S3_init(aiori_mod_opt_t * options){
+  WARN("S3 initialized");
+  count_init++;
+}
+
+static void S3_final(aiori_mod_opt_t * options){
+  WARN("S3 finalized");
+  if(count_init <= 0){
+    ERR("S3 invalid finalization\n");
+  }
+  count_init--;
+}
+
+
+ior_aiori_t S3_libS3_aiori = {
+        .name = "S3-libs3",
+        .name_legacy = NULL,
+        .create = S3_Create,
+        .open = S3_Open,
+        .xfer = S3_Xfer,
+        .close = S3_Close,
+        .delete = S3_Delete,
+        .get_version = S3_getVersion,
+        .fsync = S3_Fsync,
+        .get_file_size = S3_GetFileSize,
+        .statfs = S3_statfs,
+        .mkdir = S3_mkdir,
+        .rmdir = S3_rmdir,
+        .access = S3_access,
+        .stat = S3_stat,
+        .initialize = S3_init,
+        .finalize = S3_final,
+        .get_options = S3_options,
+        .check_params = S3_check_params,
+        .sync = S3_Sync,
+        .enable_mdtest = true
+};
diff --git a/src/aiori.c b/src/aiori.c
index 303f367..7b0c160 100644
--- a/src/aiori.c
+++ b/src/aiori.c
@@ -68,8 +68,11 @@ ior_aiori_t *available_aiori[] = {
 #ifdef USE_MMAP_AIORI
         &mmap_aiori,
 #endif
-#ifdef USE_S3_AIORI
-        &s3_aiori,
+#ifdef USE_S3_LIBS3_AIORI
+        &S3_libS3_aiori,
+#endif
+#ifdef USE_S3_4C_AIORI
+        &s3_4c_aiori,
         &s3_plus_aiori,
         &s3_emc_aiori,
 #endif
diff --git a/src/aiori.h b/src/aiori.h
index f7205e0..6b185d7 100755
--- a/src/aiori.h
+++ b/src/aiori.h
@@ -130,7 +130,8 @@ extern ior_aiori_t ncmpi_aiori;
 extern ior_aiori_t posix_aiori;
 extern ior_aiori_t pmdk_aiori;
 extern ior_aiori_t mmap_aiori;
-extern ior_aiori_t s3_aiori;
+extern ior_aiori_t S3_libS3_aiori;
+extern ior_aiori_t s3_4c_aiori;
 extern ior_aiori_t s3_plus_aiori;
 extern ior_aiori_t s3_emc_aiori;
 extern ior_aiori_t rados_aiori;