diff --git a/Surface_mesh/examples/Surface_mesh/sm_properties.cpp b/Surface_mesh/examples/Surface_mesh/sm_properties.cpp
index 1e4c1a8a36a..1779dee5a33 100644
--- a/Surface_mesh/examples/Surface_mesh/sm_properties.cpp
+++ b/Surface_mesh/examples/Surface_mesh/sm_properties.cpp
@@ -14,6 +14,10 @@ int main()
 {
 
   Mesh m;
+  std::cin >> m;
+  std::cout << m << std::endl;
+
+  m.clear();
   vertex_descriptor v0 = m.add_vertex(K::Point_3(0,2,0));
   vertex_descriptor v1 = m.add_vertex(K::Point_3(2,2,0));
   vertex_descriptor v2 = m.add_vertex(K::Point_3(0,0,0));
@@ -25,7 +29,6 @@ int main()
   m.add_face(v2, v3, v4);
 
 
-
   // give each vertex a name, the default is empty
   Mesh::Property_map<vertex_descriptor,std::string> name;
   bool created;
@@ -59,6 +62,8 @@ int main()
   // delete the string property again
   m.remove_property_map(name);
 
+  std::cout << m <<std::endl;
+
   return 0;
 }
 
diff --git a/Surface_mesh/include/CGAL/Surface_mesh/IO.h b/Surface_mesh/include/CGAL/Surface_mesh/IO.h
index be7f27f39dc..d2d9499885e 100644
--- a/Surface_mesh/include/CGAL/Surface_mesh/IO.h
+++ b/Surface_mesh/include/CGAL/Surface_mesh/IO.h
@@ -66,13 +66,13 @@ bool read_off_binary(Surface_mesh<Point_3>& mesh,
     Point_3            p;
     Vector_3           n, c;
     Vector_2           t;
-    typename Mesh::Vertex_descriptor  v;
+    typename Mesh::Vertex_index  v;
 
     // properties
-    Property_map<typename Mesh::Vertex_descriptor, Normal>              normals;
-    Property_map<typename Mesh::Vertex_descriptor, Texture_coordinate>  texcoords;
-    if (has_normals)   normals   = mesh.template get_property_map<typename Mesh::Vertex_descriptor, Normal>("v:normal");
-    if (has_texcoords) texcoords = mesh.template get_property_map<typename Mesh::Vertex_descriptor, Texture_coordinate>("v:texcoord");
+    Mesh::Property_map<typename Mesh::Vertex_index, Normal>              normals;
+    Mesh::Property_map<typename Mesh::Vertex_index, Texture_coordinate>  texcoords;
+    if (has_normals)   normals   = mesh.template get_or_add_property_map<typename Mesh::Vertex_index, Normal>("v:normal");
+    if (has_texcoords) texcoords = mesh.template get_or_add_property_map<typename Mesh::Vertex_index, Texture_coordinate>("v:texcoord");
 
 
     // #Vertice, #Faces, #Edges
@@ -107,7 +107,7 @@ bool read_off_binary(Surface_mesh<Point_3>& mesh,
 
 
     // read faces: #N v[1] v[2] ... v[n-1]
-    std::vector<typename Mesh::Vertex_descriptor> vertices;
+    std::vector<typename Mesh::Vertex_index> vertices;
     for (i=0; i<nF; ++i)
     {
         internal::read(in, nV);
@@ -115,7 +115,7 @@ bool read_off_binary(Surface_mesh<Point_3>& mesh,
         for (j=0; j<nV; ++j)
         {
             internal::read(in, idx);
-            vertices[j] = typename Mesh::Vertex_descriptor(idx);
+            vertices[j] = typename Mesh::Vertex_index(idx);
         }
         if(!mesh.add_face(vertices).is_valid()) {
           // adding a face did not succeed, stop reading the rest
@@ -142,14 +142,14 @@ bool read_off_ascii(Surface_mesh<Point_3>& mesh,
     char                    line[100], *lp;
     unsigned int            i, j, items, idx, nc;
     unsigned int            nV, nF, nE;
-    typename Mesh::Vertex_descriptor   v;
+    typename Mesh::Vertex_index   v;
 
     // properties
-    Property_map<typename Mesh::Vertex_descriptor, Normal>                 normals;
-    Property_map<typename Mesh::Vertex_descriptor, Texture_coordinate>     texcoords;
+    Mesh::Property_map<typename Mesh::Vertex_index, Normal>                 normals;
+    Mesh::Property_map<typename Mesh::Vertex_index, Texture_coordinate>     texcoords;
     
-    if (has_normals)   normals   = mesh.template get_property_map<typename Mesh::Vertex_descriptor, Normal>("v:normal");
-    if (has_texcoords) texcoords = mesh.template get_property_map<typename Mesh::Vertex_descriptor, Texture_coordinate>("v:texcoord");
+    if (has_normals)   normals   = mesh.template get_or_add_property_map<typename Mesh::Vertex_index, Normal>("v:normal");
+    if (has_texcoords) texcoords = mesh.template get_or_add_property_map<typename Mesh::Vertex_index, Texture_coordinate>("v:texcoord");
 
     int c;
     do {
@@ -206,7 +206,7 @@ bool read_off_ascii(Surface_mesh<Point_3>& mesh,
     }
 
     // read faces: #N v[1] v[2] ... v[n-1]
-    std::vector<typename Mesh::Vertex_descriptor> vertices;
+    std::vector<typename Mesh::Vertex_index> vertices;
     for (i=0; i<nF; ++i)
     {
         // read line
@@ -228,7 +228,7 @@ bool read_off_ascii(Surface_mesh<Point_3>& mesh,
         {
             items = sscanf(lp, "%d%n", (int*)&idx, &nc);
             CGAL_assertion(items == 1);
-            vertices[j] = typename Mesh::Vertex_descriptor(idx);
+            vertices[j] = typename Mesh::Vertex_index(idx);
             lp += nc;
         }
 
@@ -343,8 +343,8 @@ bool write_off(const Surface_mesh<K>& mesh, const std::string& filename)
 
 
     // vertices
-    Property_map<typename Mesh::Vertex_descriptor, Point_3> points 
-      = mesh.template get_property_map<typename Mesh::Vertex_descriptor, Point_3>("v:point");
+    Mesh::Property_map<typename Mesh::Vertex_index, Point_3> points 
+      = mesh.template property_map<typename Mesh::Vertex_index, Point_3>("v:point");
     for (typename Mesh::Vertex_iterator vit=mesh.vertices_begin(); vit!=mesh.vertices_end(); ++vit)
     {
         const Point_3& p = points[*vit];
diff --git a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
index 1178f8ae52f..26874dddf2f 100644
--- a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
+++ b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
@@ -1955,8 +1955,6 @@ private: //--------------------------------------------------- property handling
     }
 
 
-
-  /// @cond CGAL_DOCUMENT_INTERNALS
     /// returns a property map with key `I` and value type `T` with 
     /// `name`. If no such property exists one is added with the default
     /// value `t`.
@@ -1966,7 +1964,7 @@ private: //--------------------------------------------------- property handling
     {
         return (this->*boost::fusion::at_key<I>(pmap_)).template get_or_add<T>(name, t);
     }
-  /// @endcond
+
 
     /// removes property map `p`. The memory allocated for that property map is
     /// freed.
@@ -2091,8 +2089,28 @@ private: //------------------------------------------------------- private data
   template <typename P>
   std::ostream& operator<<(std::ostream& os, const Surface_mesh<P>& sm)
   {
+    typedef Surface_mesh<P> Mesh;
+    typedef typename Mesh::Vertex_index Vertex_index;
+    typedef typename Mesh::Face_index Face_index;
+
+    os << "OFF\n" << sm.num_vertices() << " " << sm.num_faces() << " 0\n";
+    std::vector<int> reindex;
+    reindex.resize(sm.num_vertices());
+    int n = 0;
+    BOOST_FOREACH(Vertex_index v, sm.vertices()){
+      os << sm.point(v) << std::endl;
+      reindex[v]=n++;
+    }
+
+    BOOST_FOREACH(Face_index f, sm.faces()){
+      os << sm.degree(f);
+      BOOST_FOREACH(Vertex_index v, CGAL::vertices_around_face(sm.halfedge(f),sm)){
+        os << " " << reindex[v];
+      }
+      os << "\n";
+    }
     return os;
-  }
+    }
   /// \relates Surface_mesh
   /// Extracts the surface mesh from an input stream in Ascii OFF format.
   /// If the vertices have the property "v:normal" it is also extracted from the stream.
@@ -2100,6 +2118,32 @@ private: //------------------------------------------------------- private data
   template <typename P>
   std::istream& operator>>(std::istream& is, Surface_mesh<P>& sm)
   {
+    typedef Surface_mesh<P> Mesh;
+    typedef typename Mesh::Vertex_index Vertex_index;
+    typedef typename Mesh::Face_index Face_index;
+    typedef typename Mesh::size_type size_type;
+    sm.clear();
+    int n, f, e;
+    std::string off;
+    is >> off;
+    assert(off == "OFF");
+    is >> n >> f >> e;
+    sm.reserve(n,2*f,e);
+    P p;
+    for(int i=0; i < n; i++){
+      is >> p;
+      sm.add_vertex(p);
+    }
+    std::vector<size_type> vr;
+    std::size_t d;
+    for(std::size_t i=0; i < f; i++){
+      is >> d;
+      vr.resize(d);
+      for(std::size_t j=0; j<d; j++){
+        is >> vr[j];
+      }
+      sm.add_face(vr);
+    }
     return is;
   }
 
@@ -2363,12 +2407,11 @@ Surface_mesh<P>::add_face(const Range& r)
     // test for topological errors
     for (i=0, ii=1; i<n; ++i, ++ii, ii%=n)
     {
-        if ( !is_border(vertices[i]) )
+      if ( !(is_isolated(vertices[i]) || is_border(vertices[i]) ) )
         {
             std::cerr << "Surface_meshT::add_face: complex vertex " << vertices[i] << std::endl;
             return Face_index();
         }
-
         halfedges[i] = halfedge(vertices[i], vertices[ii]);
         is_new[i]    = !halfedges[i].is_valid();
         if (!is_new[i] && !is_border(halfedges[i]))