diff --git a/ltests.c b/ltests.c
new file mode 100644
index 00000000..547d5c8b
--- /dev/null
+++ b/ltests.c
@@ -0,0 +1,273 @@
+/*
+** $Id: lbuiltin.c,v 1.83 1999/12/07 12:05:34 roberto Exp $
+** Internal Module for Debugging of the Lua Implementation
+** See Copyright Notice in lua.h
+*/
+
+
+#include <ctype.h>
+#include <stdlib.h>
+
+#define LUA_REENTRANT
+
+#include "lapi.h"
+#include "lauxlib.h"
+#include "lmem.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "lua.h"
+
+
+void luaB_opentests (lua_State *L);
+
+
+/*
+** The whole module only makes sense with DEBUG on
+*/
+#ifdef DEBUG
+
+
+static void mem_query (lua_State *L) {
+  lua_pushnumber(L, totalmem);
+  lua_pushnumber(L, numblocks);
+}
+
+
+static void hash_query (lua_State *L) {
+  lua_Object o = luaL_nonnullarg(L, 1);
+  if (lua_getparam(L, 2) == LUA_NOOBJECT) {
+    luaL_arg_check(L, ttype(o) == LUA_T_STRING, 1, "string expected");
+    lua_pushnumber(L, tsvalue(o)->hash);
+  }
+  else {
+    const Hash *t = avalue(luaL_tablearg(L, 2));
+    lua_pushnumber(L, luaH_mainposition(t, o) - t->node);
+  }
+}
+
+
+static void table_query (lua_State *L) {
+  const Hash *t = avalue(luaL_tablearg(L, 1));
+  int i = luaL_opt_int(L, 2, -1);
+  if (i == -1) {
+    lua_pushnumber(L, t->size);
+    lua_pushnumber(L, t->firstfree - t->node);
+  }
+  else if (i < t->size) {
+    luaA_pushobject(L, &t->node[i].key);
+    luaA_pushobject(L, &t->node[i].val);
+    if (t->node[i].next)
+      lua_pushnumber(L, t->node[i].next - t->node);
+  }
+}
+
+
+static void query_strings (lua_State *L) {
+  int h = luaL_check_int(L, 1) - 1;
+  int s = luaL_opt_int(L, 2, 0) - 1;
+  if (s==-1) {
+    if (h < NUM_HASHS) {
+      lua_pushnumber(L, L->string_root[h].nuse);
+      lua_pushnumber(L, L->string_root[h].size);
+    }
+  }
+  else {
+    TaggedString *ts = L->string_root[h].hash[s];
+    for (ts = L->string_root[h].hash[s]; ts; ts = ts->nexthash) {
+      if (ts->constindex == -1) lua_pushstring(L, "<USERDATA>");
+      else lua_pushstring(L, ts->str);
+    }
+  }
+}
+
+
+static const char *delimits = " \t\n,;";
+
+static void skip (const char **pc) {
+  while (**pc != '\0' && strchr(delimits, **pc)) (*pc)++;
+}
+
+static int getnum (const char **pc) {
+  int res = 0;
+  skip(pc);
+  while (isdigit(**pc)) res = res*10 + (*(*pc)++) - '0';
+  return res;
+}
+  
+static int getreg (lua_State *L, const char **pc) {
+  skip(pc);
+  if (*(*pc)++ != 'r') lua_error(L, "`testC' expecting a register");
+  return getnum(pc);
+}
+
+static const char *getname (const char **pc) {
+  static char buff[30];
+  int i = 0;
+  skip(pc);
+  while (**pc != '\0' && !strchr(delimits, **pc))
+    buff[i++] = *(*pc)++;
+  buff[i] = '\0';
+  return buff;
+}
+
+
+#define EQ(s1)	(strcmp(s1, inst) == 0)
+
+/*
+** function to test the API with C. It interprets a kind of "assembler"
+** language with calls to the API, so the test can be driven by Lua code
+*/
+static void testC (lua_State *L) {
+  lua_Object reg[10];
+  const char *pc = luaL_check_string(L, 1);
+  for (;;) {
+    const char *inst = getname(&pc);
+    if EQ("") return;
+    else if EQ("pushnum") {
+      lua_pushnumber(L, getnum(&pc));
+    }
+    else if EQ("createtable") {
+      reg[getreg(L, &pc)] = lua_createtable(L);
+    }
+    else if EQ("closure") {
+      lua_CFunction f = lua_getcfunction(L, lua_getglobal(L, getname(&pc)));
+      lua_pushcclosure(L, f, getnum(&pc));
+    }
+    else if EQ("pop") {
+      reg[getreg(L, &pc)] = lua_pop(L);
+    }
+    else if EQ("getglobal") {
+      int n = getreg(L, &pc);
+      reg[n] = lua_getglobal(L, getname(&pc));
+    }
+    else if EQ("rawgetglobal") {
+      int n = getreg(L, &pc);
+      reg[n] = lua_rawgetglobal(L, getname(&pc));
+    }
+    else if EQ("ref") {
+      lua_pushnumber(L, lua_ref(L, 0));
+      reg[getreg(L, &pc)] = lua_pop(L);
+    }
+    else if EQ("reflock") {
+      lua_pushnumber(L, lua_ref(L, 1));
+      reg[getreg(L, &pc)] = lua_pop(L);
+    }
+    else if EQ("getref") {
+      int n = getreg(L, &pc);
+      reg[n] = lua_getref(L, (int)lua_getnumber(L, reg[getreg(L, &pc)]));
+    }
+    else if EQ("unref") {
+      lua_unref(L, (int)lua_getnumber(L, reg[getreg(L, &pc)]));
+    }
+    else if EQ("getparam") {
+      int n = getreg(L, &pc);
+      reg[n] = lua_getparam(L, getnum(&pc)+1);  /* skips the commmand itself */
+    }
+    else if EQ("getresult") {
+      int n = getreg(L, &pc);
+      reg[n] = lua_getparam(L, getnum(&pc));
+    }
+    else if EQ("setglobal") {
+      lua_setglobal(L, getname(&pc));
+    }
+    else if EQ("rawsetglobal") {
+      lua_rawsetglobal(L, getname(&pc));
+    }
+    else if EQ("pushstring") {
+      lua_pushstring(L, getname(&pc));
+    }
+    else if EQ("pushreg") {
+      lua_pushobject(L, reg[getreg(L, &pc)]);
+    }
+    else if EQ("call") {
+      lua_call(L, getname(&pc));
+    }
+    else if EQ("gettable") {
+      reg[getreg(L, &pc)] = lua_gettable(L);
+    }
+    else if EQ("rawgettable") {
+      reg[getreg(L, &pc)] = lua_rawgettable(L);
+    }
+    else if EQ("settable") {
+      lua_settable(L);
+    }
+    else if EQ("rawsettable") {
+      lua_rawsettable(L);
+    }
+    else if EQ("nextvar") {
+      lua_pushstring(L, lua_nextvar(L, lua_getstring(L, reg[getreg(L, &pc)])));
+    }
+    else if EQ("next") {
+      int n = getreg(L, &pc);
+      n = lua_next(L, reg[n], (int)lua_getnumber(L, reg[getreg(L, &pc)]));
+      lua_pushnumber(L, n);
+    }
+    else if EQ("equal") {
+      int n1 = getreg(L, &pc);
+      int n2 = getreg(L, &pc);
+      lua_pushnumber(L, lua_equal(L, reg[n1], reg[n2]));
+    }
+    else if EQ("pushusertag") {
+      int val = getreg(L, &pc);
+      int tag = getreg(L, &pc);
+      lua_pushusertag(L, (void *)(int)lua_getnumber(L, reg[val]),
+                         (int)lua_getnumber(L, reg[tag]));
+    }
+    else if EQ("udataval") {
+      int n = getreg(L, &pc);
+      lua_pushnumber(L, (int)lua_getuserdata(L, reg[getreg(L, &pc)]));
+      reg[n] = lua_pop(L);
+    }
+    else if EQ("settagmethod") {
+      int n = getreg(L, &pc);
+      lua_settagmethod(L, (int)lua_getnumber(L, reg[n]), getname(&pc));
+    }
+    else if EQ("beginblock") {
+      lua_beginblock(L);
+    }
+    else if EQ("endblock") {
+      lua_endblock(L);
+    }
+    else if EQ("newstate") {
+      int stacksize = getnum(&pc);
+      lua_State *L1 = lua_newstate("stack", stacksize,
+                                   "builtin", getnum(&pc), NULL);
+      lua_pushuserdata(L, L1);
+    }
+    else if EQ("closestate") {
+      lua_close(lua_getuserdata(L, reg[getreg(L, &pc)]));
+    }
+    else if EQ("doremote") {
+      lua_Object ol1 = reg[getreg(L, &pc)];
+      lua_Object str = reg[getreg(L, &pc)];
+      lua_State *L1;
+      lua_Object temp;
+      int i;
+      if (!lua_isuserdata(L, ol1) || !lua_isstring(L, str))
+        lua_error(L, "bad arguments for `doremote'");
+      L1 = lua_getuserdata(L, ol1);
+      lua_dostring(L1, lua_getstring(L, str));
+      i = 1;
+      while ((temp = lua_getresult(L1, i++)) != LUA_NOOBJECT)
+        lua_pushstring(L, lua_getstring(L1, temp));
+    }
+    else luaL_verror(L, "unknown command in `testC': %.20s", inst);
+  }
+}
+
+
+static const struct luaL_reg tests_funcs[] = {
+  {"hash", hash_query},
+  {"querystr", query_strings},
+  {"querytab", table_query},
+  {"testC", testC},
+  {"totalmem", mem_query}
+};
+
+
+void luaB_opentests (lua_State *L) {
+  luaL_openl(L, tests_funcs);
+}
+
+#endif