diff --git a/configure b/configure
index f710333..0972494 100755
--- a/configure
+++ b/configure
@@ -13131,12 +13131,12 @@ if test -n "$DEPS_CFLAGS"; then
     pkg_cv_DEPS_CFLAGS="$DEPS_CFLAGS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libpcre check\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "libpcre check") 2>&5
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libpcre check gvc\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libpcre check gvc") 2>&5
   ac_status=$?
   $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_DEPS_CFLAGS=`$PKG_CONFIG --cflags "libpcre check" 2>/dev/null`
+  pkg_cv_DEPS_CFLAGS=`$PKG_CONFIG --cflags "libpcre check gvc" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -13148,12 +13148,12 @@ if test -n "$DEPS_LIBS"; then
     pkg_cv_DEPS_LIBS="$DEPS_LIBS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libpcre check\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "libpcre check") 2>&5
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libpcre check gvc\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libpcre check gvc") 2>&5
   ac_status=$?
   $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_DEPS_LIBS=`$PKG_CONFIG --libs "libpcre check" 2>/dev/null`
+  pkg_cv_DEPS_LIBS=`$PKG_CONFIG --libs "libpcre check gvc" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -13174,14 +13174,14 @@ else
         _pkg_short_errors_supported=no
 fi
         if test $_pkg_short_errors_supported = yes; then
-	        DEPS_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libpcre check" 2>&1`
+	        DEPS_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libpcre check gvc" 2>&1`
         else
-	        DEPS_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libpcre check" 2>&1`
+	        DEPS_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libpcre check gvc" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
 	echo "$DEPS_PKG_ERRORS" >&5
 
-	as_fn_error $? "Package requirements (libpcre check) were not met:
+	as_fn_error $? "Package requirements (libpcre check gvc) were not met:
 
 $DEPS_PKG_ERRORS
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 230a1c4..e6711bc 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,5 +1,5 @@
 lib_LTLIBRARIES=libr3.la
-libr3_la_SOURCES=node.c edge.c list.c str.c token.c
+libr3_la_SOURCES=node.c edge.c list.c str.c token.c gvc.c
 libr3_la_LIBADD=$(DEPS_LIBS)
 AM_CFLAGS=$(DEPS_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include
 # AM_CFLAGS=$(DEPS_CFLAGS)
diff --git a/src/Makefile.in b/src/Makefile.in
index d1281ce..8f9af8f 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -123,7 +123,7 @@ am__installdirs = "$(DESTDIR)$(libdir)"
 LTLIBRARIES = $(lib_LTLIBRARIES)
 am__DEPENDENCIES_1 =
 libr3_la_DEPENDENCIES = $(am__DEPENDENCIES_1)
-am_libr3_la_OBJECTS = node.lo edge.lo list.lo str.lo token.lo
+am_libr3_la_OBJECTS = node.lo edge.lo list.lo str.lo token.lo gvz.lo
 libr3_la_OBJECTS = $(am_libr3_la_OBJECTS)
 AM_V_lt = $(am__v_lt_@AM_V@)
 am__v_lt_ = $(am__v_lt_@AM_DEFAULT_V@)
@@ -312,7 +312,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 lib_LTLIBRARIES = libr3.la
-libr3_la_SOURCES = node.c edge.c list.c str.c token.c
+libr3_la_SOURCES = node.c edge.c list.c str.c token.c gvz.c
 libr3_la_LIBADD = $(DEPS_LIBS)
 AM_CFLAGS = $(DEPS_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include
 all: all-am
@@ -395,6 +395,7 @@ distclean-compile:
 	-rm -f *.tab.c
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/edge.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gvz.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/list.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/node.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/str.Plo@am__quote@
diff --git a/src/gvc.c b/src/gvc.c
new file mode 100644
index 0000000..cd47844
--- /dev/null
+++ b/src/gvc.c
@@ -0,0 +1,44 @@
+/*
+ * gvz.c
+ * Copyright (C) 2014 c9s <c9s@c9smba.local>
+ *
+ * Distributed under terms of the MIT license.
+ */
+
+#include <gvc.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "r3.h"
+
+// int main(int argc, char **argv)
+int r3_tree_render_file(node * tree, char * format, char * filename)
+{
+    Agraph_t *g;
+    Agnode_t *n, *m;
+    Agedge_t *e;
+
+    /* set up a graphviz context - but only once even for multiple graphs */
+    static GVC_t *gvc;
+
+    if (!gvc) {
+        gvc = gvContext();
+    }
+
+    /* Create a simple digraph */
+    g = agopen("g", Agdirected, 0);
+
+    n = agnode(g, "n", 1);
+    m = agnode(g, "m", 1);
+    e = agedge(g, n, m, 0, 1);
+
+    /* Set an attribute - in this case one that affects the visible rendering */
+    agsafeset(n, "color", "red", "");
+    /* Use the directed graph layout engine */
+    gvLayout(gvc, g, "dot");
+    gvRenderFilename(gvc, g, format, filename);
+    gvFreeLayout(gvc, g);
+
+    agclose(g);
+    return 0;
+}
+