diff --git a/moo/bin/main.c b/moo/bin/main.c
index b68cc4a..5759c9b 100644
--- a/moo/bin/main.c
+++ b/moo/bin/main.c
@@ -240,6 +240,15 @@ int main (int argc, char* argv[])
 		return -1;
 	}
 
+	/* TODO: don't initialize debug information if debug info is not requested.
+	 *       call moo_loaddbginfo() if loading a compiled image... */
+	if (moo_initdbginfo(moo, 102400) <= -1) /* TODO: set initial debug information size from a configurable value */
+	{
+		moo_logbfmt (moo, MOO_LOG_STDERR, "ERROR: cannot initialize debug information - [%d] %js\n", moo_geterrnum(moo), moo_geterrstr(moo));
+		moo_close (moo);
+		return -1;
+	}
+
 /*
 #if defined(macintosh)
 	i = 20;
diff --git a/moo/lib/comp.c b/moo/lib/comp.c
index e70e940..e808bb4 100644
--- a/moo/lib/comp.c
+++ b/moo/lib/comp.c
@@ -6824,7 +6824,7 @@ static int add_compiled_method (moo_t* moo)
 		/* the method has been read in from the main souce stream */
 		source_file = moo->_nil;
 	}
-	
+
 	preamble_code = MOO_METHOD_PREAMBLE_NONE;
 	preamble_index = 0;
 	preamble_flags = 0;
diff --git a/moo/lib/debug.c b/moo/lib/debug.c
index 6a056d9..2268b50 100644
--- a/moo/lib/debug.c
+++ b/moo/lib/debug.c
@@ -66,3 +66,37 @@ void moo_dumpdic (moo_t* moo, moo_oop_dic_t dic, const moo_bch_t* title)
 	}
 	MOO_DEBUG0 (moo, "--------------------------------------------\n");
 }
+
+
+/* TODO: moo_loaddbginfofromimage() -> load debug information from compiled image?
+moo_storedbginfotoimage()? -> store debug information to compiled image?
+moo_compactdbginfo()? -> compact debug information by scaning dbginfo data. find class and method. if not found, drop the portion.
+*/
+
+int moo_initdbginfo (moo_t* moo, moo_oow_t capa)
+{
+	moo_dbginfo_t* info;
+
+	info = (moo_dbginfo_t*)moo_allocmem(moo, MOO_SIZEOF(*info) + capa);
+	if (!info) return -1;
+
+	info->_capa = capa;
+	info->_len = 0;
+
+	moo->dbginfo = info;
+	return 0;
+}
+
+void moo_finidbginfo (moo_t* moo)
+{
+	if (moo->dbginfo)
+	{
+		moo_freemem (moo, moo->dbginfo);
+		moo->dbginfo = MOO_NULL;
+	}
+}
+
+int moo_addmethodtodbginfo (moo_t* moo, const moo_uch_t* class_name, const moo_uch_t* method_name)
+{
+	return 0;
+}
\ No newline at end of file
diff --git a/moo/lib/moo.c b/moo/lib/moo.c
index a254e55..12bda5a 100644
--- a/moo/lib/moo.c
+++ b/moo/lib/moo.c
@@ -249,6 +249,8 @@ void moo_fini (moo_t* moo)
 	 * the heap may not exist */
 	if (moo->heap) moo_killheap (moo, moo->heap);
 
+	moo_finidbginfo (moo);
+
 	for (i = 0; i < MOO_COUNTOF(moo->sbuf); i++)
 	{
 		if (moo->sbuf[i].ptr)
diff --git a/moo/lib/moo.h b/moo/lib/moo.h
index 1bcddc7..27628d0 100644
--- a/moo/lib/moo.h
+++ b/moo/lib/moo.h
@@ -944,6 +944,14 @@ struct moo_heap_t
 	moo_space_t  newspace;
 };
 
+typedef struct moo_dbginfo_t moo_dbginfo_t;
+struct moo_dbginfo_t
+{
+	moo_oow_t _capa;
+	moo_oow_t _len;
+	/* actual information is recorded here */
+};
+
 /* =========================================================================
  * VM LOGGING
  * ========================================================================= */
@@ -1423,6 +1431,7 @@ struct moo_t
 	/* ========================= */
 
 	moo_heap_t* heap;
+	moo_dbginfo_t* dbginfo;
 
 	/* =============================================================
 	 * nil, true, false
@@ -2050,6 +2059,14 @@ MOO_EXPORT int moo_invoke (
 	const moo_oocs_t* mthname
 );
 
+
+/**
+ * The moo_abort() function requests to stop on-going execution. 
+ * On-going execution doesn't get terminated immediately when this function
+ * returns. Termination of execution is honored by the virtual machine.
+ * If the virtual machine is in a blocking context, termination will only
+ * occur after it gets out of the blocking context.
+ */
 MOO_EXPORT void moo_abort (
 	moo_t* moo
 );
@@ -2061,6 +2078,23 @@ MOO_EXPORT void moo_abort (
 #	define moo_switchprocess(moo) ((moo)->switch_proc = 1)
 #endif
 
+/* =========================================================================
+ * DEBUG SUPPORT
+ * ========================================================================= */
+
+MOO_EXPORT int moo_initdbginfo (
+	moo_t*    moo,
+	moo_oow_t init_capa
+);
+
+/**
+ * The moo_finidbginfo() function deletes the debug information.
+ * It is called by moo_close(). Unless you want the debug information to
+ * be deleted earlier, you need not call this function explicitly.
+ */
+MOO_EXPORT void moo_finidbginfo (
+	moo_t* moo
+);
 /* =========================================================================
  * COMMON OBJECT MANAGEMENT FUNCTIONS
  * ========================================================================= */