diff --git a/vlib/example/main_stub.c b/vlib/example/main_stub.c
new file mode 100644
index 0000000..4213d91
--- /dev/null
+++ b/vlib/example/main_stub.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <math.h>
+
+int main (int argc, char * argv[])
+{
+  return vlib_unix_main (argc, argv);
+}
+
+static clib_error_t *
+main_stub_init (vlib_main_t * vm)
+{
+  clib_error_t * error;
+
+  if ((error = unix_physmem_init (vm, /* fail_if_physical_memory_not_present */ 0)))
+    return error;
+
+ if ((error = vlib_call_init_function (vm, unix_cli_init)))
+   return error;
+
+ return error;
+}
+
+VLIB_INIT_FUNCTION (main_stub_init);
+
+#if 0
+/* Node test code. */
+typedef struct {
+  int scalar;
+  int vector[0];
+} my_frame_t;
+
+static u8 * format_my_node_frame (u8 * s, va_list * va)
+{
+  vlib_frame_t * f = va_arg (*va, vlib_frame_t *);
+  my_frame_t * g = vlib_frame_args (f);
+  int i;
+
+  s = format (s, "scalar %d, vector { ", g->scalar);
+  for (i = 0; i < f->n_vectors; i++)
+    s = format (s, "%d, ", g->vector[i]);
+  s = format (s, " }");
+
+  return s;
+}
+
+static uword
+my_func (vlib_main_t * vm,
+	 vlib_node_runtime_t * rt,
+	 vlib_frame_t * f)
+{
+  vlib_node_t * node;
+  my_frame_t * y;
+  u32 i, n_left = 0;
+  static int serial;
+  int verbose;
+
+  node = vlib_get_node (vm, rt->node_index);
+
+  verbose = 0;
+
+  if (verbose && f)
+    vlib_cli_output (vm, "%v: call frame %p %U", node->name,
+		     f, format_my_node_frame, f);
+
+  if (rt->n_next_nodes > 0)
+    {
+      vlib_frame_t * next = vlib_get_next_frame (vm, rt, /* next index */ 0);
+      n_left = VLIB_FRAME_SIZE - next->n_vectors;
+      y = vlib_frame_args (next);
+      y->scalar = serial++;
+    }
+  else
+    y = 0;
+
+  for (i = 0; i < 5; i++)
+    {
+      if (y)
+	{
+	  ASSERT (n_left > 0);
+	  n_left--;
+	  y->vector[i] = y->scalar + i;
+	}
+    }
+  if (y)
+    vlib_put_next_frame (vm, rt, /* next index */ 0, n_left);
+
+  if (verbose)
+    vlib_cli_output (vm, "%v: return frame %p", node->name, f);
+
+  return i;
+}
+
+VLIB_REGISTER_NODE (my_node1,static) = {
+  .function = my_func,
+  .type = VLIB_NODE_TYPE_INPUT,
+  .name = "my-node1",
+  .scalar_size = sizeof (my_frame_t),
+  .vector_size = STRUCT_SIZE_OF (my_frame_t, vector[0]),
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "my-node2",
+  },
+};
+
+VLIB_REGISTER_NODE (my_node2,static) = {
+  .function = my_func,
+  .name = "my-node2",
+  .scalar_size = sizeof (my_frame_t),
+  .vector_size = STRUCT_SIZE_OF (my_frame_t, vector[0]),
+};
+
+#endif
+
+#if 0
+
+typedef enum {
+  MY_EVENT_TYPE1,
+  MY_EVENT_TYPE2,
+} my_process_completion_type_t;
+
+typedef struct {
+  int a;
+  f64 b;
+} my_process_event_data_t;
+
+static u8 * format_my_process_event_data (u8 * s, va_list * va)
+{
+  my_process_event_data_t * d = va_arg (*va, my_process_event_data_t *);
+  return format (s, "{ a %d b %.6f}", d->a, d->b);
+}
+
+static uword
+my_proc (vlib_main_t * vm,
+	 vlib_node_runtime_t * rt,
+	 vlib_frame_t * f)
+{
+  vlib_node_t * node;
+  u32 i;
+
+  node = vlib_get_node (vm, rt->node_index);
+
+  vlib_cli_output (vm, "%v: call frame %p", node->name, f);
+
+  for (i = 0; i < 5; i++)
+    {
+      vlib_cli_output (vm, "%v: %d", node->name, i);
+      vlib_process_suspend (vm, 1e0 /* secs */);
+    }
+
+  vlib_cli_output (vm, "%v: return frame %p", node->name, f);
+
+  if (0)
+    {
+      uword n_events_seen, type, * data = 0;
+
+      for (n_events_seen = 0; n_events_seen < 2;)
+	{
+	  vlib_process_wait_for_event (vm);
+	  type = vlib_process_get_events (vm, &data);
+	  n_events_seen += vec_len (data);
+	  vlib_cli_output (vm, "%U %v: completion #%d type %d data 0x%wx",
+			   format_time_interval, "h:m:s:u", vlib_time_now (vm),
+			   node->name, i, type, data[0]);
+	  _vec_len (data) = 0;
+	}
+
+      vec_free (data);
+    }
+  else
+    {
+      uword n_events_seen, i, type;
+      my_process_event_data_t * data;
+      for (n_events_seen = 0; n_events_seen < 2;)
+	{
+	  vlib_process_wait_for_event (vm);
+	  data = vlib_process_get_event_data (vm, &type);
+	  vec_foreach_index (i, data) {
+	    vlib_cli_output (vm, "%U event type %d data %U",
+			     format_time_interval, "h:m:s:u", vlib_time_now (vm),
+			     type, format_my_process_event_data, data);
+	  }
+	  n_events_seen += vec_len (data);
+	  vlib_process_put_event_data (vm, data);
+	}
+    }
+
+  return i;
+}
+
+VLIB_REGISTER_NODE (my_proc_node,static) = {
+  .function = my_proc,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "my-proc",
+};
+
+static uword
+my_proc_input (vlib_main_t * vm,
+	       vlib_node_runtime_t * rt,
+	       vlib_frame_t * f)
+{
+  static int i;
+
+  if (i++ < 2)
+    {
+      if (0)
+	vlib_process_signal_event (vm, my_proc_node.index,
+				   i == 1 ? MY_EVENT_TYPE1 : MY_EVENT_TYPE2,
+				   0x12340000 + i);
+      else
+	{
+	  my_process_event_data_t * d;
+	  f64 dt = 5;
+	  d = vlib_process_signal_event_at_time (vm,
+						 i * dt,
+						 my_proc_node.index,
+						 i == 1 ? MY_EVENT_TYPE1 : MY_EVENT_TYPE2,
+						 1 /* elts */,
+						 sizeof (d[0]));
+	  d->a = i;
+	  d->b = vlib_time_now (vm);
+	}
+    }
+  else
+    vlib_node_set_state (vm, rt->node_index, VLIB_NODE_STATE_DISABLED);
+
+  return 0; 
+}
+
+VLIB_REGISTER_NODE (my_proc_input_node,static) = {
+  .function = my_proc_input,
+  .type = VLIB_NODE_TYPE_INPUT,
+  .name = "my-proc-input",
+};
+
+static uword _unformat_farith (unformat_input_t * i, va_list * args)
+{
+  u32 prec = va_arg (*args, u32);
+  f64 * result = va_arg (*args, f64 *);
+  f64 tmp[2];
+
+  /* Binary operations in from lowest to highest precedence. */
+  char * binops[] = {
+    "+%U", "-%U", "/%U", "*%U", "^%U",
+  };
+
+  if (prec <= ARRAY_LEN (binops) - 1
+      && unformat_user (i, _unformat_farith, prec + 1, &tmp[0]))
+    {
+      int p;
+      for (p = prec; p < ARRAY_LEN (binops); p++)
+	{
+	  if (unformat (i, binops[p],
+			_unformat_farith, prec + 0, &tmp[1]))
+	    {
+	      switch (binops[p][0])
+		{
+		case '+': result[0] = tmp[0] + tmp[1]; break;
+		case '-': result[0] = tmp[0] - tmp[1]; break;
+		case '/': result[0] = tmp[0] / tmp[1]; break;
+		case '*': result[0] = tmp[0] * tmp[1]; break;
+		case '^': result[0] = pow (tmp[0], tmp[1]); break;
+		default: abort ();
+		}
+	      return 1;
+	    }
+	}
+      result[0] = tmp[0];
+      return 1;
+    }
+
+  else if (unformat (i, "-%U",
+		     _unformat_farith, prec + 0, &tmp[0]))
+    {
+      result[0] = -tmp[0];
+      return 1;
+    }
+
+  else if (unformat (i, "(%U)",
+		     _unformat_farith, 0, &tmp[0]))
+    {
+      result[0] = tmp[0];
+      return 1;
+    }
+
+  else if (unformat (i, "%f", result))
+    return 1;
+
+  else
+    return 0;
+}
+
+static uword unformat_farith (unformat_input_t * i, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  f64 * result = va_arg (*args, f64 *);
+  return unformat_user (i, _unformat_farith, 0, result);
+}
+
+static uword unformat_integer (unformat_input_t * i, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  u32 * data = va_arg (*args, u32 *);
+  return unformat (i, "%d", data);
+}
+
+static VLIB_CLI_PARSE_RULE (my_parse_rule1) = {
+  .name = "decimal_integer",
+  .short_help = "a decimal integer",
+  .unformat_function = unformat_integer,
+  .data_size = sizeof (u32),
+};
+
+static VLIB_CLI_PARSE_RULE (my_parse_rule2) = {
+  .name = "float_expression",
+  .short_help = "floating point expression",
+  .unformat_function = unformat_farith,
+  .data_size = sizeof (f64),
+};
+
+static clib_error_t *
+bar_command (vlib_main_t * vm,
+	     unformat_input_t * input,
+	     vlib_cli_command_t * cmd)
+{
+  switch (cmd->function_arg)
+    {
+    case 2: {
+      u32 * d, * e;
+      d = vlib_cli_get_parse_rule_result (vm, 0);
+      e = vlib_cli_get_parse_rule_result (vm, 1);
+      vlib_cli_output (vm, "bar2 %d %d", d[0], e[0]);
+      break;
+    }
+
+    case 1: {
+      u32 * d = vlib_cli_get_parse_rule_result (vm, 0);
+      vlib_cli_output (vm, "bar1 %d", d[0]);
+      break;
+    }
+
+    case 3: {
+      f64 * d = vlib_cli_get_parse_rule_result (vm, 0);
+      vlib_cli_output (vm, "expr %.6f", d[0]);
+    }
+    }
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (bar_command2, static) = {
+  .path = "bar %decimal_integer",
+  .short_help = "bar1 command",
+  .function = bar_command,
+  .function_arg = 1,
+};
+VLIB_CLI_COMMAND (bar_command1, static) = {
+  .path = "bar %decimal_integer %decimal_integer",
+  .short_help = "bar2 command",
+  .function = bar_command,
+  .function_arg = 2,
+};
+VLIB_CLI_COMMAND (bar_command3, static) = {
+  .path = "zap %float_expression",
+  .short_help = "bar3 command",
+  .function = bar_command,
+  .function_arg = 3,
+};
+
+#endif
+
diff --git a/vlib/example/mc_test.c b/vlib/example/mc_test.c
new file mode 100644
index 0000000..2a7fe98
--- /dev/null
+++ b/vlib/example/mc_test.c
@@ -0,0 +1,370 @@
+/*
+ * mc_test.c: test program for vlib mc
+ *
+ * Copyright (c) 2010 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vlib/unix/mc_socket.h>
+#include <vppinfra/random.h>
+
+typedef struct {
+  u32 min_n_msg_bytes;
+  u32 max_n_msg_bytes;
+  u32 tx_serial;
+  u32 rx_serial;
+  u32 seed;
+  u32 verbose;
+  u32 validate;
+  u32 window_size;
+  f64 min_delay, max_delay;
+  f64 n_packets_to_send;
+} mc_test_main_t;
+
+always_inline u32
+choose_msg_size (mc_test_main_t * tm)
+{
+  u32 r = tm->min_n_msg_bytes;
+  if (tm->max_n_msg_bytes > tm->min_n_msg_bytes)
+    r += random_u32 (&tm->seed) % (1 + tm->max_n_msg_bytes - tm->min_n_msg_bytes);
+  return r;
+}
+
+static mc_test_main_t mc_test_main;
+
+static void serialize_test_msg (serialize_main_t * m, va_list * va)
+{
+  mc_test_main_t * tm = &mc_test_main;
+  u32 n_bytes = choose_msg_size (tm);
+  u8 * msg;
+  int i;
+  serialize_integer (m, n_bytes, sizeof (n_bytes));
+  msg = serialize_get (m, n_bytes);
+  for (i = 0; i < n_bytes; i++)
+    msg[i] = i + tm->tx_serial;
+  tm->tx_serial += n_bytes;
+}
+
+static void unserialize_test_msg (serialize_main_t * m, va_list * va)
+{
+  mc_test_main_t * tm = &mc_test_main;
+  u32 i, n_bytes, dump_msg = tm->verbose;
+  u8 * p;
+  unserialize_integer (m, &n_bytes, sizeof (n_bytes));
+  p = unserialize_get (m, n_bytes);
+  if (tm->validate)
+    for (i = 0; i < n_bytes; i++)
+      if (p[i] != ((tm->rx_serial + i) & 0xff))
+	{
+	  clib_warning ("corrupt msg at offset %d", i);
+	  dump_msg = 1;
+	  break;
+	}
+  if (dump_msg)
+    clib_warning ("got %d bytes, %U", n_bytes, format_hex_bytes, p, n_bytes);
+  tm->rx_serial += n_bytes;
+}
+
+MC_SERIALIZE_MSG (test_msg, static) = {
+  .name = "test_msg",
+  .serialize = serialize_test_msg,
+  .unserialize = unserialize_test_msg,
+};
+
+#define SERIALIZE 1
+
+#define EVENT_JOIN_STREAM 	10
+#define EVENT_SEND_DATA 	11
+
+static void test_rx_callback (mc_main_t * mcm,
+			      mc_stream_t * stream,
+			      mc_peer_id_t peer_id,
+			      u32 buffer_index)
+{
+  if (SERIALIZE)
+    {
+        return mc_unserialize (mcm, stream, buffer_index);
+    }
+  else
+    {
+#if DEBUG > 1
+      vlib_main_t * vm = mcm->vlib_main;
+      vlib_buffer_t * b = vlib_get_buffer (vm, buffer_index);
+      u8 * dp = vlib_buffer_get_current (b);
+
+      fformat(stdout, "RX from %U %U\n",
+	      stream->transport->format_peer_id, peer_id,
+	      format_hex_bytes, dp, tm->n_msg_bytes);
+            
+#endif
+    }
+}
+
+static u8 *
+test_snapshot_callback (mc_main_t * mcm,
+			u8 * data_vector,
+			u32 last_global_sequence_processed)
+{
+  if (SERIALIZE)
+    {
+      serialize_main_t m;
+
+      /* Append serialized data to data vector. */
+      serialize_open_vector (&m, data_vector);
+      m.stream.current_buffer_index = vec_len (data_vector);
+
+      return serialize_close_vector (&m);
+    }
+  else
+    return format (data_vector,
+		   "snapshot, last global seq 0x%x",
+		   last_global_sequence_processed);
+}
+
+static void
+test_handle_snapshot_callback (mc_main_t * mcm,
+			       u8 * data,
+			       u32 n_data_bytes)
+{
+  if (SERIALIZE)
+    {
+      serialize_main_t s;
+      unserialize_open_data (&s, data, n_data_bytes);
+    }
+  else
+    clib_warning ("snapshot `%*s'", n_data_bytes, data);
+}
+
+static mc_socket_main_t mc_socket_main;
+
+static uword
+mc_test_process (vlib_main_t * vm,
+		 vlib_node_runtime_t * node,
+		 vlib_frame_t * f)
+{
+  mc_test_main_t * tm = &mc_test_main;
+  mc_socket_main_t * msm = &mc_socket_main;
+  mc_main_t *mcm = &msm->mc_main;
+  uword event_type, *event_data = 0;
+  u32 data_serial=0, stream_index;
+  f64 delay;
+  mc_stream_config_t config;
+  clib_error_t * error;
+  int i;
+  char *intfcs[] =  { "eth1", "eth0", "ce" };
+
+  memset (&config, 0, sizeof (config));
+  config.name = "test";
+  config.window_size = tm->window_size;
+  config.rx_buffer = test_rx_callback;
+  config.catchup_snapshot = test_snapshot_callback;
+  config.catchup = test_handle_snapshot_callback;
+  stream_index = ~0;
+
+  msm->multicast_tx_ip4_address_host_byte_order = 0xefff0100;
+  msm->base_multicast_udp_port_host_byte_order = 0xffab;
+
+  error = mc_socket_main_init (&mc_socket_main, intfcs, ARRAY_LEN(intfcs));
+  if (error)
+    {
+      clib_error_report (error);
+      exit (1);
+    }
+
+  mcm->we_can_be_relay_master = 1;
+
+  while (1)
+    {
+      vlib_process_wait_for_event (vm);
+      event_type = vlib_process_get_events (vm, &event_data);
+
+      switch (event_type)
+	{
+	case EVENT_JOIN_STREAM:
+	  stream_index = mc_stream_join (mcm, &config);
+	  break;
+
+	case EVENT_SEND_DATA: {
+          f64 times[2];
+
+          if (stream_index == ~0)
+	    stream_index = mc_stream_join (mcm, &config);
+
+          times[0] = vlib_time_now (vm);
+	  for (i = 0; i < event_data[0]; i++)
+	    {
+	      u32 bi;
+	      if (SERIALIZE)
+		{
+		  mc_serialize_stream (mcm, stream_index, &test_msg, data_serial);
+		}
+	      else
+		{
+		  u8 * mp;
+		  mp = mc_get_vlib_buffer (vm, sizeof (mp[0]), &bi);
+		  mp[0] = data_serial;
+		  mc_stream_send (mcm, stream_index, bi);
+		}
+	      if (tm->min_delay > 0)
+		{
+		  delay = tm->min_delay + random_f64 (&tm->seed) * (tm->max_delay - tm->min_delay);
+		  vlib_process_suspend (vm, delay);
+		}
+	      data_serial++;
+	    }
+          times[1] = vlib_time_now (vm);
+          clib_warning ("done sending %d; %.4e per sec",
+                        event_data[0],
+                        (f64) event_data[0] / (times[1] - times[0]));
+	  break;
+        }
+
+	default:
+	  clib_warning ("bug");
+	  break;
+	}
+            
+      if (event_data)
+	_vec_len (event_data) = 0;
+    }
+}
+
+VLIB_REGISTER_NODE (mc_test_process_node,static) = {
+  .function = mc_test_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "mc-test-process",
+};
+
+static clib_error_t *
+mc_test_command (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  f64 npkts = 10;
+
+  if (unformat (input, "join"))
+    {
+      vlib_cli_output (vm, "Join stream...\n");
+      vlib_process_signal_event (vm, mc_test_process_node.index,
+				 EVENT_JOIN_STREAM, 0);
+      return 0;
+    }
+  else if (unformat (input, "send %f", &npkts) 
+	   || unformat(input, "send"))
+    {
+      vlib_process_signal_event (vm, mc_test_process_node.index,
+				 EVENT_SEND_DATA, (uword) npkts);
+      vlib_cli_output (vm, "Send %.0f pkts...\n", npkts);
+    
+      return 0;
+    }
+  else
+    return unformat_parse_error (input);
+}
+
+VLIB_CLI_COMMAND (test_mc_command, static) = {
+  .path = "test mc",
+  .short_help = "Test mc command",
+  .function = mc_test_command,
+};
+
+static clib_error_t *
+mc_show_command (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  mc_main_t *mcm = &mc_socket_main.mc_main;
+  vlib_cli_output (vm, "%U", format_mc_main, mcm);
+  return 0;
+}
+
+VLIB_CLI_COMMAND (show_mc_command, static) = {
+  .path = "show mc",
+  .short_help = "Show mc command",
+  .function = mc_show_command,
+};
+
+static clib_error_t *
+mc_clear_command (vlib_main_t * vm,
+		  unformat_input_t * input,
+		  vlib_cli_command_t * cmd)
+{
+  mc_main_t * mcm = &mc_socket_main.mc_main;
+  mc_clear_stream_stats (mcm);
+  return 0;
+}
+
+VLIB_CLI_COMMAND (clear_mc_command, static) = {
+  .path = "clear mc",
+  .short_help = "Clear mc command",
+  .function = mc_clear_command,
+};
+
+static clib_error_t *
+mc_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  mc_test_main_t * tm = &mc_test_main;
+  mc_socket_main_t * msm = &mc_socket_main;
+  clib_error_t * error = 0;
+
+  tm->min_n_msg_bytes = 4;
+  tm->max_n_msg_bytes = 4;
+  tm->window_size = 8;
+  tm->seed = getpid ();
+  tm->verbose = 0;
+  tm->validate = 1;
+  tm->min_delay = 10e-6;
+  tm->max_delay = 10e-3;
+  tm->n_packets_to_send = 0;
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "interface %s", &msm->multicast_interface_name))
+	;
+
+      else if (unformat (input, "n-bytes %d", &tm->max_n_msg_bytes))
+	tm->min_n_msg_bytes = tm->max_n_msg_bytes;
+      else if (unformat (input, "max-n-bytes %d", &tm->max_n_msg_bytes))
+	;
+      else if (unformat (input, "min-n-bytes %d", &tm->min_n_msg_bytes))
+	;
+      else if (unformat (input, "seed %d", &tm->seed))
+	;
+      else if (unformat (input, "window %d", &tm->window_size))
+	;
+      else if (unformat (input, "verbose"))
+	tm->verbose = 1;
+      else if (unformat (input, "no-validate"))
+	tm->validate = 0;
+      else if (unformat (input, "min-delay %f", &tm->min_delay))
+	;
+      else if (unformat (input, "max-delay %f", &tm->max_delay))
+	;
+      else if (unformat (input, "no-delay"))
+	tm->min_delay = tm->max_delay = 0;
+      else if (unformat (input, "n-packets %f", &tm->n_packets_to_send))
+	;
+
+      else
+	return clib_error_return (0, "unknown input `%U'",
+				  format_unformat_error, input);
+    }
+
+  if (tm->n_packets_to_send > 0)
+    vlib_process_signal_event (vm, mc_test_process_node.index,
+			       EVENT_SEND_DATA, (uword) tm->n_packets_to_send);
+
+  return error;
+}
+
+VLIB_CONFIG_FUNCTION (mc_config, "mc");
diff --git a/vlib/example/plex_test.c b/vlib/example/plex_test.c
new file mode 100644
index 0000000..947f25b
--- /dev/null
+++ b/vlib/example/plex_test.c
@@ -0,0 +1,490 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vlib/parse.h>
+#include <vlib/unix/unix.h>
+
+static u8 * format_value_v4_address (u8 * s, va_list * args)
+{
+  vlib_parse_value_t *v = va_arg (*args, vlib_parse_value_t *);
+  u32 a = v->value.as_uword;
+
+  s = format (s, "%d.%d.%d.%d",
+	      (a>>24) & 0xFF,
+	      (a>>16) & 0xFF,
+	      (a>>8)  & 0xFF,
+	      (a>>0)  & 0xFF);
+
+  return s;
+}
+
+static vlib_parse_match_t
+v4_address_match (vlib_parse_main_t *pm, vlib_parse_type_t *type, 
+		  vlib_lex_token_t *t, vlib_parse_value_t *valuep)
+{
+  u32 digit;
+  u32 value = 0;
+  int i;
+
+  if (vec_len (pm->tokens) - (t - pm->tokens) < 7)
+    return VLIB_PARSE_MATCH_FAIL;
+
+  /* NUMBER DOT NUMBER DOT NUMBER DOT NUMBER */
+
+  for (i = 0; i < 7; i++) {
+    if ((i & 1) == 0) {
+      if (t[i].token != VLIB_LEX_number)
+	return VLIB_PARSE_MATCH_FAIL;
+      if (t[i].value.as_uword > 0xff)
+	return VLIB_PARSE_MATCH_FAIL;
+      digit = t[i].value.as_uword;
+      value = (value << 8) | digit;
+    } else {
+      if (t[i].token != VLIB_LEX_dot)
+	return VLIB_PARSE_MATCH_FAIL;
+    }
+  }
+  /* note: caller advances by 1 */
+  pm->current_token_index += 6;
+  valuep->value.as_uword = value;
+  return VLIB_PARSE_MATCH_VALUE;
+}
+
+PARSE_TYPE_INIT (v4_address, v4_address_match, 0, format_value_v4_address)
+
+static u8 * format_value_v4_address_and_mask (u8 * s, va_list * args)
+{
+  vlib_parse_value_t *v = va_arg (*args, vlib_parse_value_t *);
+  u32 * a = v->value.as_pointer;
+
+  s = format (s, "%d.%d.%d.%d",
+	      (a[0]>>24) & 0xFF,
+	      (a[0]>>16) & 0xFF,
+	      (a[0]>>8)  & 0xFF,
+	      (a[0]>>0)  & 0xFF);
+  s = format (s, "/%d", a[1]);
+
+  return s;
+}
+
+static vlib_parse_match_t
+v4_address_and_mask_match (vlib_parse_main_t *pm, vlib_parse_type_t *type, 
+			   vlib_lex_token_t *t, vlib_parse_value_t *valuep)
+{
+  u32 digit;
+  u32 address = 0;
+  u32 *rv = 0;
+  int i;
+
+  if (vec_len (pm->tokens) - (t - pm->tokens) < 9)
+    return VLIB_PARSE_MATCH_FAIL;
+
+  /* NUMBER DOT NUMBER DOT NUMBER DOT NUMBER */
+
+  for (i = 0; i < 7; i++) {
+    if ((i & 1) == 0) {
+      if (t[i].token != VLIB_LEX_number)
+	return VLIB_PARSE_MATCH_FAIL;
+      if (t[i].value.as_uword > 0xff)
+	return VLIB_PARSE_MATCH_FAIL;
+      digit = t[i].value.as_uword;
+      address = (address << 8) | digit;
+    } else {
+      if (t[i].token != VLIB_LEX_dot)
+	return VLIB_PARSE_MATCH_FAIL;
+    }
+  }
+
+  if (t[7].token != VLIB_LEX_slash || t[8].token != VLIB_LEX_number)
+    return VLIB_PARSE_MATCH_FAIL;
+
+  vec_add1 (rv, address);
+  vec_add1 (rv, t[8].value.as_uword);
+
+  /* note: caller advances by 1 */
+  pm->current_token_index += 8;
+  valuep->value.as_pointer = rv;
+  return VLIB_PARSE_MATCH_VALUE;
+}
+
+void v4_address_and_mask_cleanup (vlib_parse_value_t *valuep)
+{
+  u32 * trash = valuep->value.as_pointer;
+  vec_free (trash);
+}
+
+PARSE_TYPE_INIT (v4_address_and_mask, v4_address_and_mask_match, 
+                 v4_address_and_mask_cleanup, 
+                 format_value_v4_address_and_mask)
+
+vlib_lex_main_t vlib_lex_main;
+
+
+
+vlib_parse_match_t eval_factor0 (vlib_parse_main_t *pm, 
+                                 vlib_parse_item_t *item,
+                                 vlib_parse_value_t *value)
+{
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_factor1 (vlib_parse_main_t *pm, 
+                                 vlib_parse_item_t *item,
+                                 vlib_parse_value_t *value)
+{
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_factor2 (vlib_parse_main_t *pm, 
+                                 vlib_parse_item_t *item,
+                                 vlib_parse_value_t *value)
+{
+  word a;
+  int index = vec_len (pm->parse_value)-1;
+  
+  a = pm->parse_value [index].value.as_word;
+  
+  pm->parse_value[index].value.as_word = -a;
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_term0 (vlib_parse_main_t *pm, 
+                               vlib_parse_item_t *item,
+                               vlib_parse_value_t *value)
+{
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_term1 (vlib_parse_main_t *pm, 
+                               vlib_parse_item_t *item,
+                               vlib_parse_value_t *value)
+{
+  uword a, b;
+  int index = vec_len (pm->parse_value)-2;
+  
+  a = pm->parse_value [index].value.as_uword;
+  b = pm->parse_value [index+1].value.as_uword;
+  
+  pm->parse_value[index].value.as_uword = a * b;
+  _vec_len (pm->parse_value) -= 1;
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_term2 (vlib_parse_main_t *pm, 
+                               vlib_parse_item_t *item,
+                               vlib_parse_value_t *value)
+{
+  uword a, b;
+  int index = vec_len (pm->parse_value)-2;
+  
+  a = pm->parse_value [index].value.as_uword;
+  b = pm->parse_value [index+1].value.as_uword;
+  
+  pm->parse_value[index].value.as_uword = a / b;
+  _vec_len (pm->parse_value) -= 1;
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_exp0 (vlib_parse_main_t *pm, 
+                              vlib_parse_item_t *item,
+                              vlib_parse_value_t *value)
+{
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_exp1 (vlib_parse_main_t *pm, 
+                              vlib_parse_item_t *item,
+                              vlib_parse_value_t *value)
+{
+  uword a, b;
+  int index = vec_len (pm->parse_value)-2;
+  
+  a = pm->parse_value [index].value.as_uword;
+  b = pm->parse_value [index+1].value.as_uword;
+  
+  pm->parse_value[index].value.as_uword = a + b;
+  _vec_len (pm->parse_value) -= 1;
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  
+  return VLIB_PARSE_MATCH_RULE;
+}
+vlib_parse_match_t eval_exp2 (vlib_parse_main_t *pm, 
+                              vlib_parse_item_t *item,
+                              vlib_parse_value_t *value)
+{
+  uword a, b;
+  int index = vec_len (pm->parse_value)-2;
+  
+  a = pm->parse_value [index].value.as_uword;
+  b = pm->parse_value [index+1].value.as_uword;
+  
+  pm->parse_value[index].value.as_uword = a - b;
+  _vec_len (pm->parse_value) -= 1;
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  
+  return VLIB_PARSE_MATCH_RULE;
+}
+
+vlib_parse_match_t eval_result (vlib_parse_main_t *pm, 
+                                vlib_parse_item_t *item,
+                                vlib_parse_value_t *value)
+{
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  return VLIB_PARSE_MATCH_DONE;
+}
+
+vlib_parse_match_t noop_match_rule (vlib_parse_main_t *pm, 
+                               vlib_parse_item_t *item,
+                               vlib_parse_value_t *value)
+{
+  clib_warning ("%U", format_vlib_parse_value, pm);
+  return VLIB_PARSE_MATCH_RULE;
+}
+
+#if 0
+PARSE_INIT (t1, "moo", eval0);
+PARSE_INIT (t2, "moo cow mumble", eval1);
+PARSE_INIT (t3, "moo cow", eval2);
+PARSE_INIT (t4, "moo cow mumble grunch", eval3);
+#endif
+
+#if 0
+PARSE_INIT (r1, "eval <exp>", eval_result);
+
+PARSE_INIT (r2, "<exp> = <term><exp2>", eval_exp0);
+PARSE_INIT (r3, "<exp2> = <plus> <exp>", eval_exp1);
+PARSE_INIT (r4, "<exp2> = <minus> <exp>", eval_exp2);
+PARSE_INIT (r5, "<exp2> = ", noop_match_rule);
+PARSE_TYPE_INIT (exp, rule_match, 0, 0);
+PARSE_TYPE_INIT (exp2, rule_match, 0, 0);
+
+PARSE_INIT (r6, "<term> = <factor><term2>", eval_term0);
+PARSE_INIT (r7, "<term2> = <star> <term>", eval_term1);
+PARSE_INIT (r8, "<term2> = <slash> <term>", eval_term2);
+PARSE_INIT (r9, "<term2> = ", noop_match_rule);
+PARSE_TYPE_INIT (term, rule_match, 0, 0);
+PARSE_TYPE_INIT (term2, rule_match, 0, 0);
+
+PARSE_INIT (r11, "<factor> = <lpar> <exp> <rpar>", eval_factor1);
+PARSE_INIT (r10, "<factor> = <number>", eval_factor0);
+PARSE_INIT (r12, "<factor> = <minus> <factor>", eval_factor2);
+
+PARSE_TYPE_INIT (factor, rule_match, 0, 0);
+#endif
+
+PARSE_INIT (r1, "eval <exp>", eval_result);
+
+#if 1
+PARSE_INIT (r2, "<exp> = <term><exp2>", eval_exp0);
+PARSE_INIT (r3, "<exp2> = <plus> <exp>", eval_exp1);
+PARSE_INIT (r4, "<exp2> = <minus> <exp>", eval_exp2);
+PARSE_INIT (r5, "<exp2> = ", noop_match_rule);
+PARSE_TYPE_INIT (exp, rule_match, 0, 0);
+PARSE_TYPE_INIT (exp2, rule_match, 0, 0);
+
+PARSE_INIT (r6, "<term> = <factor><term2>", eval_term0);
+PARSE_INIT (r7, "<term2> = <star> <term>", eval_term1);
+PARSE_INIT (r8, "<term2> = <slash> <term>", eval_term2);
+PARSE_INIT (r9, "<term2> = ", noop_match_rule);
+PARSE_TYPE_INIT (term, rule_match, 0, 0);
+PARSE_TYPE_INIT (term2, rule_match, 0, 0);
+
+PARSE_INIT (r11, "<factor> = <lpar> <exp> <rpar>", eval_factor1);
+PARSE_INIT (r10, "<factor> = <number>", eval_factor0);
+PARSE_INIT (r12, "<factor> = <minus> <factor>", eval_factor2);
+
+PARSE_TYPE_INIT (factor, rule_match, 0, 0);
+#endif
+
+#if 0
+PARSE_TYPE_INIT (exp, rule_match, 0, 0);
+PARSE_INIT (r6, "<exp> = a b", eval_term0);
+PARSE_INIT (r7, "<exp> = c d", eval_term1);
+PARSE_INIT (r9, "<exp> = ", noop_match_rule);
+#endif
+
+#if 0
+#define foreach_rule_evaluator                  \
+_(0)                                            \
+_(1)                                            \
+_(2)						\
+_(3)
+
+#define _(n)                                            \
+vlib_parse_match_t eval##n (vlib_parse_main_t *pm,      \
+                            vlib_parse_item_t *item,    \
+                            vlib_parse_value_t *value)  \
+{                                                       \
+  clib_warning ("%U", format_vlib_parse_value, pm);     \
+  return VLIB_PARSE_MATCH_DONE;                         \
+}
+foreach_rule_evaluator
+
+#undef _
+
+PARSE_INIT (r1, "eval <moo>", eval_result);
+
+PARSE_INIT (r2, "<moo> = cow", eval0);
+PARSE_INIT (r4, "<moo> = ", eval1);
+PARSE_TYPE_INIT (moo, rule_match, 0, 0);
+#endif 
+
+
+clib_error_t *test_init (vlib_main_t *vm)
+{
+  clib_error_t *error;
+
+  if ((error = vlib_call_init_function (vm, parse_init)))
+    return error;
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (test_init);
+
+clib_error_t *
+vlib_stdlex_init (vlib_main_t * vm)
+{
+  vlib_lex_main_t * lm = &vlib_lex_main;
+  u16 top_index;
+  u16 slash_index, slash_star_index, slash_slash_index, slash_star_star_index;
+  u16 slash_token;
+  u16 word_index;
+  u16 zero_index, octal_index, decimal_index, hex_index, binary_index;
+    
+  top_index = vlib_lex_add_table ("top");
+
+#define foreach_top_level_single_character_token        \
+  _('(', lpar)                                          \
+  _(')', rpar)                                          \
+  _(';', semi)                                          \
+  _('[', lbrack)                                        \
+  _(']', rbrack)                                        \
+  _('{', lcurly)                                        \
+  _('}', rcurly)                                        \
+  _('+', plus)                                          \
+  _('-', minus)                                         \
+  _('*', star)                                          \
+  _('%', percent)                                       \
+  _('@', atsign)                                        \
+  _(',', comma)                                         \
+  _('.', dot)                                           \
+  _('?', qmark)
+
+#define _(c,t) \
+  vlib_lex_set_action_range(top_index,c,c,VLIB_LEX_RETURN,vlib_lex_add_token(lm, #t), top_index);
+  foreach_top_level_single_character_token;
+#undef _
+
+  /* Numbers */
+  zero_index = vlib_lex_add_table ("zero");
+  octal_index = vlib_lex_add_table ("octal");
+  decimal_index = vlib_lex_add_table ("decimal");
+  hex_index = vlib_lex_add_table ("hex");
+  binary_index = vlib_lex_add_table ("binary");
+
+  /* Support 0x 0b 0t and 0123 [octal] */
+  vlib_lex_set_action_range (top_index, '0', '0', VLIB_LEX_START_NUMBER, 10, zero_index);
+  vlib_lex_set_action_range (top_index, '1', '9', VLIB_LEX_START_NUMBER, 10, decimal_index);
+
+  vlib_lex_set_action_range (zero_index, 0, 0x7F, VLIB_LEX_RETURN_AND_RESCAN, VLIB_LEX_number, top_index);
+
+  vlib_lex_set_action_range (zero_index, 'x', 'x', VLIB_LEX_IGNORE, ~0, hex_index); 
+  vlib_lex_set_action_range (zero_index, 'b', 'b', VLIB_LEX_IGNORE, ~0, binary_index); 
+  vlib_lex_set_action_range (zero_index, 't', 't', VLIB_LEX_IGNORE, ~0, decimal_index); 
+  vlib_lex_set_action_range (zero_index, '0', '7', VLIB_LEX_START_NUMBER, 8, octal_index);
+    
+  /* Octal */
+  vlib_lex_set_action_range (octal_index, 0, 0x7f, VLIB_LEX_RETURN_AND_RESCAN,
+			VLIB_LEX_number, top_index);
+  vlib_lex_set_action_range (octal_index, '0', '7', VLIB_LEX_ADD_TO_NUMBER, 8, 
+			octal_index);
+
+  /* Decimal */
+  vlib_lex_set_action_range (decimal_index, 0, 0x7f, VLIB_LEX_RETURN_AND_RESCAN,
+			VLIB_LEX_number, top_index);
+  vlib_lex_set_action_range (decimal_index, '0', '9', VLIB_LEX_ADD_TO_NUMBER, 10, 
+			decimal_index);
+    
+  /* Hex */
+  vlib_lex_set_action_range (hex_index, 0, 0x7f, VLIB_LEX_RETURN_AND_RESCAN,
+			VLIB_LEX_number, top_index);
+  vlib_lex_set_action_range (hex_index, '0', '9', VLIB_LEX_ADD_TO_NUMBER, 16, 
+			hex_index);
+  vlib_lex_set_action_range (hex_index, 'a', 'f', VLIB_LEX_ADD_TO_NUMBER, 16, 
+			hex_index);
+  vlib_lex_set_action_range (hex_index, 'A', 'F', VLIB_LEX_ADD_TO_NUMBER, 16, 
+			hex_index);
+    
+  /* Binary */
+  vlib_lex_set_action_range (binary_index, 0, 0x7f, VLIB_LEX_RETURN_AND_RESCAN,
+			VLIB_LEX_number, top_index);
+  vlib_lex_set_action_range (binary_index, '0', '1', VLIB_LEX_ADD_TO_NUMBER, 2, 
+			binary_index);
+
+  /* c/c++ comment syntax is the worst... */
+
+  slash_index = vlib_lex_add_table ("slash");
+  slash_star_index = vlib_lex_add_table ("slash_star");
+  slash_star_star_index = vlib_lex_add_table ("slash_star_star");
+  slash_slash_index = vlib_lex_add_table ("slash_slash");
+  slash_token = vlib_lex_add_token (lm, "slash");
+
+  /* Top level: see a slash, ignore, go to slash table */
+  vlib_lex_set_action_range (top_index, '/', '/', VLIB_LEX_IGNORE, ~0, slash_index);
+
+  /* default for slash table: return SLASH, go to top table */
+  vlib_lex_set_action_range (slash_index, 1, 0x7F, VLIB_LEX_RETURN_AND_RESCAN, slash_token, 
+			top_index);
+  /* see slash-slash, go to s-s table */
+  vlib_lex_set_action_range (slash_index, '/', '/', VLIB_LEX_IGNORE, ~0, 
+			slash_slash_index);
+  /* see slash-star, go to s-* table */
+  vlib_lex_set_action_range (slash_index, '*', '*', VLIB_LEX_IGNORE, ~0, 
+			slash_star_index);
+
+  /* EOL in s-s table, ignore, go to top table */
+  vlib_lex_set_action_range (slash_slash_index, '\n', '\n', VLIB_LEX_IGNORE, ~0, 
+			top_index);
+
+  /* slash-star blah blah star */
+  vlib_lex_set_action_range (slash_star_index, '*', '*', VLIB_LEX_IGNORE, ~0,
+			slash_star_star_index);
+
+  /* slash star blah blah star slash */
+  vlib_lex_set_action_range (slash_star_star_index, '/', '/', VLIB_LEX_IGNORE, ~0,
+			top_index);
+
+  /* LT, =, GT */
+  vlib_lex_set_action_range (top_index, '<', '<', VLIB_LEX_RETURN, VLIB_LEX_lt, top_index);
+  vlib_lex_set_action_range (top_index, '=', '=', VLIB_LEX_RETURN, VLIB_LEX_equals,
+			top_index);
+  vlib_lex_set_action_range (top_index, '>', '>', VLIB_LEX_RETURN, VLIB_LEX_gt, top_index);
+
+  /* words, key and otherwise */
+  word_index = vlib_lex_add_table ("word");
+
+  vlib_lex_set_action_range (top_index, 'a', 'z', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+  vlib_lex_set_action_range (top_index, 'A', 'Z', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+
+  vlib_lex_set_action_range (word_index, 0, 0x7f, VLIB_LEX_KEYWORD_CHECK, ~0, top_index);
+
+  vlib_lex_set_action_range (word_index, 'a', 'z', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+  vlib_lex_set_action_range (word_index, 'A', 'Z', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+  vlib_lex_set_action_range (word_index, '_', '_', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+  vlib_lex_set_action_range (word_index, '0', '9', VLIB_LEX_ADD_TO_TOKEN, ~0, word_index);
+    
+  return 0;
+}
+