diff --git a/src/OpenMesh/Core/IO/BinaryHelper.cc b/src/OpenMesh/Core/IO/BinaryHelper.cc
index 6162b00c..eb55699c 100644
--- a/src/OpenMesh/Core/IO/BinaryHelper.cc
+++ b/src/OpenMesh/Core/IO/BinaryHelper.cc
@@ -240,6 +240,66 @@ void write_double(double _d, FILE* _out, bool _swap)
   fwrite((char*)dc.c, 1, 8, _out);
 }
 
+
+//-----------------------------------------------------------------------------
+
+
+void write_short(short int _i, std::ostream& _out, bool _swap)
+{
+  union u1 { short int s; unsigned char c[2]; } sc;
+  sc.s = _i;
+  if (_swap) std::swap(sc.c[0], sc.c[1]);
+  _out.write((char*)sc.c, 2);
+}
+
+
+//-----------------------------------------------------------------------------
+
+
+void write_int(int _i, std::ostream& _out, bool _swap)
+{
+  union u2 { int i; unsigned char c[4]; } ic;
+  ic.i = _i;
+  if (_swap) {
+    std::swap(ic.c[0], ic.c[3]);
+    std::swap(ic.c[1], ic.c[2]);
+  }
+  _out.write((char*)ic.c, 4);
+}
+
+
+//-----------------------------------------------------------------------------
+
+
+void write_float(float _f, std::ostream& _out, bool _swap)
+{
+  union u3 { float f; unsigned char c[4]; } fc;
+  fc.f = _f;
+  if (_swap) {
+    std::swap(fc.c[0], fc.c[3]);
+    std::swap(fc.c[1], fc.c[2]);
+  }
+  _out.write((char*)fc.c, 4);
+}
+
+
+//-----------------------------------------------------------------------------
+
+
+void write_double(double _d, std::ostream& _out, bool _swap)
+{
+  union u4 { double d; unsigned char c[8]; } dc;
+  dc.d = _d;
+  if (_swap) {
+    std::swap(dc.c[0], dc.c[7]);
+    std::swap(dc.c[1], dc.c[6]);
+    std::swap(dc.c[2], dc.c[5]);
+    std::swap(dc.c[3], dc.c[4]);
+  }
+  _out.write((char*)dc.c, 8);
+}
+
+
 #endif
 
 //=============================================================================
diff --git a/src/OpenMesh/Core/IO/BinaryHelper.hh b/src/OpenMesh/Core/IO/BinaryHelper.hh
index ef862f11..d470d565 100644
--- a/src/OpenMesh/Core/IO/BinaryHelper.hh
+++ b/src/OpenMesh/Core/IO/BinaryHelper.hh
@@ -129,6 +129,21 @@ void write_float(float _f, FILE* _out, bool _swap=false);
     \c _swap is true */
 void write_double(double _d, FILE* _out, bool _swap=false);
 
+/** Binary write a \c short to \c _os and perform byte swapping if
+    \c _swap is true */
+void write_short(short int _i, std::ostream& _out, bool _swap=false);
+
+/** Binary write an \c int to \c _os and perform byte swapping if
+    \c _swap is true */
+void write_int(int _i, std::ostream& _out, bool _swap=false);
+
+/** Binary write a \c float to \c _os and perform byte swapping if
+    \c _swap is true */
+void write_float(float _f, std::ostream& _out, bool _swap=false);
+
+/** Binary write a \c double to \c _os and perform byte swapping if
+    \c _swap is true */
+void write_double(double _d, std::ostream& _out, bool _swap=false);
 
 //@}
 
diff --git a/src/OpenMesh/Core/IO/writer/STLWriter.cc b/src/OpenMesh/Core/IO/writer/STLWriter.cc
index 8444ea17..36fef3f7 100644
--- a/src/OpenMesh/Core/IO/writer/STLWriter.cc
+++ b/src/OpenMesh/Core/IO/writer/STLWriter.cc
@@ -4,10 +4,10 @@
  *      Copyright (C) 2001-2011 by Computer Graphics Group, RWTH Aachen      *
  *                           www.openmesh.org                                *
  *                                                                           *
- *---------------------------------------------------------------------------* 
+ *---------------------------------------------------------------------------*
  *  This file is part of OpenMesh.                                           *
  *                                                                           *
- *  OpenMesh is free software: you can redistribute it and/or modify         * 
+ *  OpenMesh is free software: you can redistribute it and/or modify         *
  *  it under the terms of the GNU Lesser General Public License as           *
  *  published by the Free Software Foundation, either version 3 of           *
  *  the License, or (at your option) any later version with the              *
@@ -30,10 +30,10 @@
  *  License along with OpenMesh.  If not,                                    *
  *  see <http://www.gnu.org/licenses/>.                                      *
  *                                                                           *
-\*===========================================================================*/ 
+\*===========================================================================*/
 
 /*===========================================================================*\
- *                                                                           *             
+ *                                                                           *
  *   $Revision$                                                         *
  *   $Date$                   *
  *                                                                           *
@@ -105,7 +105,7 @@ write(const std::string& _filename, BaseExporter& _be, Options _opt) const
   }
   else if (_filename.rfind(".stl") != std::string::npos)
   {
-    return (_opt.check( Options::Binary ) 
+    return (_opt.check( Options::Binary )
 	    ? write_stlb(_filename, _be, _opt)
 	    : write_stla(_filename, _be, _opt) );
   }
@@ -120,7 +120,20 @@ bool
 _STLWriter_::
 write(std::ostream& _os, BaseExporter& _be, Options _opt) const
 {
-  omerr() << "[STLWriter] : STL Streams are not supported " << std::endl;
+  // check exporter features
+  if (!check(_be, _opt)) return false;
+
+  // check writer features
+  if (_opt.check(Options::VertexNormal)   ||
+      _opt.check(Options::VertexTexCoord) ||
+      _opt.check(Options::FaceColor))
+    return false;
+
+  if (_opt & Options::Binary)
+    return write_stlb(_os, _be, _opt);
+  else
+    return write_stla(_os, _be, _opt);
+
   return false;
 }
 
@@ -194,6 +207,57 @@ write_stla(const std::string& _filename, BaseExporter& _be, Options /* _opt */)
 //-----------------------------------------------------------------------------
 
 
+bool
+_STLWriter_::
+write_stla(std::ostream& _out, BaseExporter& _be, Options /* _opt */) const
+{
+  omlog() << "[STLWriter] : write ascii file\n";
+
+  unsigned int i, nF(_be.n_faces()), nV;
+  Vec3f  a, b, c, n;
+  std::vector<VertexHandle> vhandles;
+  FaceHandle fh;
+  std::streamsize prec = _out.precision();
+
+
+  // header
+  _out << "solid\n";
+
+
+  // write face set
+  for (i=0; i<nF; ++i)
+  {
+    fh = FaceHandle(i);
+    nV = _be.get_vhandles(fh, vhandles);
+
+    if (nV == 3)
+    {
+      a = _be.point(vhandles[0]);
+      b = _be.point(vhandles[1]);
+      c = _be.point(vhandles[2]);
+      n = (_be.has_face_normals() ?
+     _be.normal(fh) :
+     ((c-b) % (a-b)).normalize());
+
+      _out.precision(prec);
+      _out << "facet normal " << n[0] << " " << n[1] << " " << n[2] << "\nouter loop\n";
+      _out.precision(10);
+      _out << "vertex " << a[0] << " " << a[1] << " " << a[2] << "\n";
+      _out << "vertex " << b[0] << " " << b[1] << " " << b[2] << "\n";
+      _out << "vertex " << c[0] << " " << c[1] << " " << c[2] << "\n";
+    } else {
+      omerr() << "[STLWriter] : Warning non-triangle data!\n";
+    }
+
+    _out << "\nendloop\nendfacet\n";
+  }
+
+  return true;
+}
+
+//-----------------------------------------------------------------------------
+
+
 bool
 _STLWriter_::
 write_stlb(const std::string& _filename, BaseExporter& _be, Options /* _opt */) const
@@ -272,6 +336,76 @@ write_stlb(const std::string& _filename, BaseExporter& _be, Options /* _opt */)
   return true;
 }
 
+//-----------------------------------------------------------------------------
+
+bool
+_STLWriter_::
+write_stlb(std::ostream& _out, BaseExporter& _be, Options /* _opt */) const
+{
+  omlog() << "[STLWriter] : write binary file\n";
+
+
+  unsigned int i, nF(_be.n_faces()), nV;
+  Vec3f  a, b, c, n;
+  std::vector<VertexHandle> vhandles;
+  FaceHandle fh;
+
+
+   // write header
+  const char header[80] =
+    "binary stl file"
+    "                                                                ";
+  _out.write(header, 80);
+
+
+  // number of faces
+  write_int(_be.n_faces(), _out);
+
+
+  // write face set
+  for (i=0; i<nF; ++i)
+  {
+    fh = FaceHandle(i);
+    nV = _be.get_vhandles(fh, vhandles);
+
+    if (nV == 3)
+    {
+      a = _be.point(vhandles[0]);
+      b = _be.point(vhandles[1]);
+      c = _be.point(vhandles[2]);
+      n = (_be.has_face_normals() ?
+     _be.normal(fh) :
+     ((c-b) % (a-b)).normalize());
+
+      // face normal
+      write_float(n[0], _out);
+      write_float(n[1], _out);
+      write_float(n[2], _out);
+
+      // face vertices
+      write_float(a[0], _out);
+      write_float(a[1], _out);
+      write_float(a[2], _out);
+
+      write_float(b[0], _out);
+      write_float(b[1], _out);
+      write_float(b[2], _out);
+
+      write_float(c[0], _out);
+      write_float(c[1], _out);
+      write_float(c[2], _out);
+
+      // space filler
+      write_short(0, _out);
+    }
+    else
+      omerr() << "[STLWriter] : Warning: Skipped non-triangle data!\n";
+  }
+
+
+  return true;
+}
+
 
 //-----------------------------------------------------------------------------
 
diff --git a/src/OpenMesh/Core/IO/writer/STLWriter.hh b/src/OpenMesh/Core/IO/writer/STLWriter.hh
index 15638a33..d464c2a4 100644
--- a/src/OpenMesh/Core/IO/writer/STLWriter.hh
+++ b/src/OpenMesh/Core/IO/writer/STLWriter.hh
@@ -4,10 +4,10 @@
  *      Copyright (C) 2001-2011 by Computer Graphics Group, RWTH Aachen      *
  *                           www.openmesh.org                                *
  *                                                                           *
- *---------------------------------------------------------------------------* 
+ *---------------------------------------------------------------------------*
  *  This file is part of OpenMesh.                                           *
  *                                                                           *
- *  OpenMesh is free software: you can redistribute it and/or modify         * 
+ *  OpenMesh is free software: you can redistribute it and/or modify         *
  *  it under the terms of the GNU Lesser General Public License as           *
  *  published by the Free Software Foundation, either version 3 of           *
  *  the License, or (at your option) any later version with the              *
@@ -30,10 +30,10 @@
  *  License along with OpenMesh.  If not,                                    *
  *  see <http://www.gnu.org/licenses/>.                                      *
  *                                                                           *
-\*===========================================================================*/ 
+\*===========================================================================*/
 
 /*===========================================================================*\
- *                                                                           *             
+ *                                                                           *
  *   $Revision$                                                         *
  *   $Date$                   *
  *                                                                           *
@@ -77,31 +77,33 @@ namespace IO {
 //=== IMPLEMENTATION ==========================================================
 
 
-/** 
-    Implementation of the STL format writer. This class is singleton'ed by 
+/**
+    Implementation of the STL format writer. This class is singleton'ed by
     SingletonT to STLWriter.
 */
 class OPENMESHDLLEXPORT _STLWriter_ : public BaseWriter
 {
 public:
-  
+
   _STLWriter_();
 
   /// Destructor
   virtual ~_STLWriter_() {};
-  
+
   std::string get_description() const { return "Stereolithography Format"; }
   std::string get_extensions()  const { return "stla stlb"; }
-  
+
   bool write(const std::string&, BaseExporter&, Options) const;
-  
+
   bool write(std::ostream&, BaseExporter&, Options) const;
-  
+
   size_t binary_size(BaseExporter&, Options) const;
 
 private:
   bool write_stla(const std::string&, BaseExporter&, Options) const;
+  bool write_stla(std::ostream&, BaseExporter&, Options) const;
   bool write_stlb(const std::string&, BaseExporter&, Options) const;
+  bool write_stlb(std::ostream&, BaseExporter&, Options) const;
 };