diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4b192568..0b6fbd36 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -87,6 +87,16 @@ build_ubuntu:
     - docker commit `cat netgen_${CI_BUILD_REF_NAME}_${UBUNTU_VERSION}.id` netgen_${CI_BUILD_REF_NAME}_installed:${UBUNTU_VERSION}
     - rm netgen_${CI_BUILD_REF_NAME}_${UBUNTU_VERSION}.id
 
+build_ubuntu_mpi:
+  <<: *ubuntu
+  stage: build
+  script:
+    - docker build -t netgen_mpi_${CI_BUILD_REF_NAME}:${UBUNTU_VERSION} -f tests/dockerfile_mpi .
+    - rm -f netgen_mpi_${CI_BUILD_REF_NAME}_$UBUNTU_VERSION.id_mpi
+    - docker run --cidfile netgen_mpi_${CI_BUILD_REF_NAME}_${UBUNTU_VERSION}.id -e CCACHE_DIR=/ccache -v /mnt/ccache:/ccache netgen_mpi_${CI_BUILD_REF_NAME}:${UBUNTU_VERSION} bash /root/src/netgen/tests/build_mpi.sh
+    - docker commit `cat netgen_mpi_${CI_BUILD_REF_NAME}_${UBUNTU_VERSION}.id` netgen_mpi_${CI_BUILD_REF_NAME}_installed:${UBUNTU_VERSION}
+    - rm netgen_mpi_${CI_BUILD_REF_NAME}_${UBUNTU_VERSION}.id
+
 test_ubuntu:
   <<: *ubuntu
   stage: test
@@ -98,6 +108,17 @@ test_ubuntu:
       netgen_${CI_BUILD_REF_NAME}_installed:${UBUNTU_VERSION}
       bash -c 'cd /root/build/netgen && make test_netgen ARGS="-V"'
 
+test_ubuntu_mpi:
+  <<: *ubuntu
+  stage: test
+  script:
+    - >-
+      docker run
+      -e NETGENDIR=/opt/netgen/bin
+      -e PYTHONPATH=/opt/netgen/lib/python3/dist-packages
+      netgen_mpi_${CI_BUILD_REF_NAME}_installed:${UBUNTU_VERSION}
+      bash -c 'cd /root/build/netgen && make test_netgen ARGS="-V"'
+
 # cpp guideline checks
 test_guidelines:
   <<: *ubuntu
@@ -125,6 +146,7 @@ cleanup_ubuntu:
   when: always
   allow_failure: true
 
+
 ############################################
 # MacOSX
 ############################################
diff --git a/libsrc/csg/CMakeLists.txt b/libsrc/csg/CMakeLists.txt
index eaf7dffc..98475096 100644
--- a/libsrc/csg/CMakeLists.txt
+++ b/libsrc/csg/CMakeLists.txt
@@ -12,7 +12,9 @@ if(APPLE)
 endif(APPLE)
 
 target_link_libraries(csg PUBLIC mesh ${PYTHON_LIBRARIES})
-install( TARGETS csg ${NG_INSTALL_DIR})
+if(NOT WIN32)
+  install( TARGETS csg ${NG_INSTALL_DIR})
+endif(NOT WIN32)
 
 target_link_libraries(csg PUBLIC ngcore)
 
diff --git a/libsrc/geom2d/CMakeLists.txt b/libsrc/geom2d/CMakeLists.txt
index 43c619a0..395141e5 100644
--- a/libsrc/geom2d/CMakeLists.txt
+++ b/libsrc/geom2d/CMakeLists.txt
@@ -5,7 +5,9 @@ if(APPLE)
 endif(APPLE)
 
 target_link_libraries(geom2d mesh ${PYTHON_LIBRARIES})
-install( TARGETS geom2d ${NG_INSTALL_DIR})
+if(NOT WIN32)
+  install( TARGETS geom2d ${NG_INSTALL_DIR})
+endif(NOT WIN32)
 
 target_link_libraries(geom2d ngcore)
 
diff --git a/libsrc/interface/CMakeLists.txt b/libsrc/interface/CMakeLists.txt
index afd301d9..d27061b1 100644
--- a/libsrc/interface/CMakeLists.txt
+++ b/libsrc/interface/CMakeLists.txt
@@ -9,7 +9,9 @@ add_library(interface ${NG_LIB_TYPE}
 
 target_link_libraries(interface mesh csg geom2d)
 target_link_libraries(interface visual)
-install( TARGETS interface ${NG_INSTALL_DIR})
+if(NOT WIN32)
+  install( TARGETS interface ${NG_INSTALL_DIR})
+endif(NOT WIN32)
 
 install(FILES
   writeuser.hpp
diff --git a/libsrc/interface/readuser.cpp b/libsrc/interface/readuser.cpp
index 10cb9894..abfc6775 100644
--- a/libsrc/interface/readuser.cpp
+++ b/libsrc/interface/readuser.cpp
@@ -260,6 +260,7 @@ namespace netgen
 
         Point3d pmin, pmax;
         mesh.ComputeNVertices();
+        mesh.RebuildSurfaceElementLists();
         mesh.GetBox (pmin, pmax);
         cout << "bounding-box = " << pmin << "-" << pmax << endl;
       }
diff --git a/libsrc/meshing/CMakeLists.txt b/libsrc/meshing/CMakeLists.txt
index 12fe70ae..f1e9ee86 100644
--- a/libsrc/meshing/CMakeLists.txt
+++ b/libsrc/meshing/CMakeLists.txt
@@ -24,7 +24,9 @@ endif(APPLE)
 target_link_libraries( mesh PUBLIC ngcore PRIVATE gprim la gen )
 
 target_link_libraries( mesh PUBLIC ${ZLIB_LIBRARIES} ${MPI_CXX_LIBRARIES} ${PYTHON_LIBRARIES} ${METIS_LIBRARY})
-install( TARGETS mesh ${NG_INSTALL_DIR})
+if(NOT WIN32)
+  install( TARGETS mesh ${NG_INSTALL_DIR})
+endif(NOT WIN32)
 
 install(FILES
   adfront2.hpp adfront3.hpp basegeom.hpp bcfunctions.hpp bisect.hpp
diff --git a/libsrc/meshing/curvedelems.cpp b/libsrc/meshing/curvedelems.cpp
index 98410568..83c5211f 100644
--- a/libsrc/meshing/curvedelems.cpp
+++ b/libsrc/meshing/curvedelems.cpp
@@ -409,6 +409,15 @@ namespace netgen
   
   static Array<shared_ptr<RecPol>> jacpols2;
 
+  void CurvedElements::buildJacPols()
+  {
+    if (!jacpols2.Size())
+      {
+	jacpols2.SetSize (100);
+	for (int i = 0; i < 100; i++)
+	  jacpols2[i] = make_shared<JacobiRecPol> (100, i, 2);
+      }
+  }
 
   // compute face bubbles up to order n, 0 < y, y-x < 1, x+y < 1
   template <class Tx, class Ty, class Ts>
@@ -540,7 +549,6 @@ namespace netgen
 
   CurvedElements :: ~CurvedElements()
   {
-    jacpols2.SetSize(0);
   }
 
 
@@ -719,13 +727,7 @@ namespace netgen
 
     ComputeGaussRule (aorder+4, xi, weight);  // on (0,1)
 
-    if (!jacpols2.Size())
-      {
-	jacpols2.SetSize (100);
-	for (int i = 0; i < 100; i++)
-	  jacpols2[i] = make_shared<JacobiRecPol> (100, i, 2);
-      }
-
+    buildJacPols();
     PrintMessage (3, "Curving edges");
 
     if (mesh.GetDimension() == 3 || rational)
@@ -2239,6 +2241,20 @@ namespace netgen
     
     switch (el.GetType())
       {
+      case TRIG6:
+        {
+          AutoDiff<2,T> lam3 = 1-x-y;
+          AutoDiff<2,T> lami[6] = { x * (2*x-1), y * (2*y-1), lam3 * (2*lam3-1),
+                                    4 * y * lam3, 4 * x * lam3, 4 * x * y };
+          for (int j = 0; j < 6; j++)
+            {
+              Point<3> p = mesh[el[j]];
+              for (int k = 0; k < DIM_SPACE; k++)
+                mapped_x[k] += p(k) * lami[j];
+            }
+          break;
+        }
+        
       case TRIG:
         {
           // if (info.order >= 2) return false; // not yet supported
diff --git a/libsrc/meshing/curvedelems.hpp b/libsrc/meshing/curvedelems.hpp
index 29c911aa..cd78d708 100644
--- a/libsrc/meshing/curvedelems.hpp
+++ b/libsrc/meshing/curvedelems.hpp
@@ -33,6 +33,7 @@ class CurvedElements
   bool rational;
 
   bool ishighorder;
+  void buildJacPols();
 
 public:
   DLL_HEADER CurvedElements (const Mesh & amesh);
@@ -50,6 +51,8 @@ public:
 
   virtual void DoArchive(Archive& ar)
   {
+    if(ar.Input())
+      buildJacPols();
     ar & edgeorder & faceorder & edgecoeffsindex & facecoeffsindex & edgecoeffs & facecoeffs
       & edgeweight & order & rational & ishighorder;
   }
diff --git a/libsrc/meshing/meshclass.cpp b/libsrc/meshing/meshclass.cpp
index 9acfacaa..8ae917aa 100644
--- a/libsrc/meshing/meshclass.cpp
+++ b/libsrc/meshing/meshclass.cpp
@@ -90,6 +90,7 @@ namespace netgen
 
   Mesh & Mesh :: operator= (const Mesh & mesh2)
   {
+    dimension = mesh2.dimension;
     points = mesh2.points;
     // eltyps = mesh2.eltyps;
     segments = mesh2.segments;
@@ -1320,6 +1321,7 @@ namespace netgen
     archive & segments;
     archive & facedecoding;
     archive & materials & bcnames & cd2names & cd3names;
+    archive & numvertices;
 
     archive & *ident;
 
@@ -4995,6 +4997,10 @@ namespace netgen
     // netgen::Point<3> pmin = p - Vec<3> (pointtol, pointtol, pointtol);
     // netgen::Point<3> pmax = p + Vec<3> (pointtol, pointtol, pointtol);
 
+    if ( (dimension == 2 && !GetNSE()) ||
+    	 (dimension == 3 && !GetNE() && !GetNSE()) )
+      return -1;
+
     if (dimension == 2 || (dimension==3 && !GetNE() && GetNSE()))
       {
         int ne;
diff --git a/libsrc/meshing/meshtype.cpp b/libsrc/meshing/meshtype.cpp
index 806b6c39..5eaa02d0 100644
--- a/libsrc/meshing/meshtype.cpp
+++ b/libsrc/meshing/meshtype.cpp
@@ -1140,6 +1140,7 @@ namespace netgen
       default: break;
         cerr << "Element::SetType unknown type  " << int(typ) << endl;
       }
+    is_curved = (np > 4); 
   }
 
 
diff --git a/libsrc/meshing/meshtype.hpp b/libsrc/meshing/meshtype.hpp
index 41fdb11a..a2f76986 100644
--- a/libsrc/meshing/meshtype.hpp
+++ b/libsrc/meshing/meshtype.hpp
@@ -765,11 +765,12 @@ namespace netgen
     void DoArchive (Archive & ar)
     {
       short _np, _typ;
+      bool _curved;
       if (ar.Output())
-        { _np = np; _typ = typ; }
-      ar & _np & _typ & index;
+        { _np = np; _typ = typ; _curved = is_curved; }
+      ar & _np & _typ & index & _curved;
       if (ar.Input())
-        { np = _np; typ = ELEMENT_TYPE(_typ); }
+        { np = _np; typ = ELEMENT_TYPE(_typ); is_curved = _curved; }
       for (size_t i = 0; i < np; i++)
         ar & pnum[i];
     }
diff --git a/libsrc/meshing/parallelmesh.cpp b/libsrc/meshing/parallelmesh.cpp
index 7b1248a6..45d6f98b 100644
--- a/libsrc/meshing/parallelmesh.cpp
+++ b/libsrc/meshing/parallelmesh.cpp
@@ -745,6 +745,38 @@ namespace netgen
     
     MPI_Barrier(comm);
 
+    PrintMessage( 3, "Clean up local memory");
+
+    auto & self = const_cast<Mesh&>(*this);
+    self.points = T_POINTS(0);
+    self.surfelements = T_SURFELEMENTS(0);
+    self.volelements = T_VOLELEMENTS(0);
+    self.segments = Array<Segment, 0, size_t>(0);
+    self.lockedpoints = Array<PointIndex>(0);
+    auto cleanup_ptr = [](auto & ptr) {
+      if (ptr != nullptr) {
+	delete ptr;
+	ptr = nullptr;
+      }
+    };
+    cleanup_ptr(self.boundaryedges);
+    cleanup_ptr(self.boundaryedges);
+    cleanup_ptr(self.segmentht);
+    cleanup_ptr(self.surfelementht);
+    self.openelements = Array<Element2d>(0);
+    self.opensegments = Array<Segment>(0);
+    self.numvertices = 0;
+    self.mlbetweennodes = Array<PointIndices<2>,PointIndex::BASE> (0);
+    self.mlparentelement = Array<int>(0);
+    self.mlparentsurfaceelement = Array<int>(0);
+    self.topology.Update();
+    self.curvedelems = new CurvedElements (self);
+    self.clusters = new AnisotropicClusters (self);
+    self.ident = new Identifications (self);
+    self.BuildElementSearchTree();
+    
+    // const_cast<Mesh&>(*this).DeleteMesh();
+    
     PrintMessage( 3, "send mesh complete");
   }
 
diff --git a/libsrc/meshing/python_mesh.cpp b/libsrc/meshing/python_mesh.cpp
index 5c4cfbcb..18f0ee0f 100644
--- a/libsrc/meshing/python_mesh.cpp
+++ b/libsrc/meshing/python_mesh.cpp
@@ -17,6 +17,8 @@ namespace netgen
 {
   extern bool netgen_executable_started;
   extern shared_ptr<NetgenGeometry> ng_geometry;
+  extern void Optimize2d (Mesh & mesh, MeshingParameters & mp);
+
 #ifdef PARALLEL
   /** we need allreduce in python-wrapped communicators **/
   template <typename T>
@@ -865,14 +867,21 @@ DLL_HEADER void ExportNetgenMeshing(py::module &m)
            },
           py::arg("mp")=NGDummyArgument(),py::call_guard<py::gil_scoped_release>())
 
-   .def ("OptimizeVolumeMesh", FunctionPointer
-         ([](Mesh & self)
+    .def ("OptimizeVolumeMesh", [](Mesh & self)
           {
             MeshingParameters mp;
             mp.optsteps3d = 5;
             OptimizeVolume (mp, self);
-          }),py::call_guard<py::gil_scoped_release>())
+          },py::call_guard<py::gil_scoped_release>())
 
+    .def ("OptimizeMesh2d", [](Mesh & self)
+          {
+            self.CalcLocalH(0.5);
+            MeshingParameters mp;
+            mp.optsteps2d = 5;
+            Optimize2d (self, mp);
+          },py::call_guard<py::gil_scoped_release>())
+    
     .def ("Refine", FunctionPointer
           ([](Mesh & self)
            {
@@ -975,12 +984,17 @@ DLL_HEADER void ExportNetgenMeshing(py::module &m)
           },
           py::arg("name"), py::arg("set")=true)
     
-    .def ("Scale", FunctionPointer([](Mesh & self, double factor)
-				   {
-				     for(auto i = 0; i<self.GetNP();i++)
-				       self.Point(i).Scale(factor);
-				   }))
-                                            
+    .def ("Scale", [](Mesh & self, double factor)
+          {
+            for(auto i = 0; i<self.GetNP();i++)
+              self.Point(i).Scale(factor);
+          })
+    .def ("Copy", [](Mesh & self)
+          {
+            auto m2 = make_shared<Mesh> ();
+            *m2 = self;
+            return m2;
+          })
     ;
 
   m.def("ImportMesh", [](const string& filename)
diff --git a/libsrc/visualization/vssolution.cpp b/libsrc/visualization/vssolution.cpp
index 65505e5e..64ed1818 100644
--- a/libsrc/visualization/vssolution.cpp
+++ b/libsrc/visualization/vssolution.cpp
@@ -4005,8 +4005,8 @@ namespace netgen
     Array<int> compress(n3);
 
     NgProfiler::StartTimer (timer_vals);
-    Array<double,PointIndex::BASE> vertval(mesh->GetNV());
-    Array<bool,PointIndex::BASE> posval(mesh->GetNV());
+    Array<double,PointIndex::BASE> vertval(mesh->GetNP());
+    Array<bool,PointIndex::BASE> posval(mesh->GetNP());
     for (PointIndex pi = vertval.Begin(); pi < vertval.End(); pi++)
       {
         Point<3> vert = (*mesh)[pi];
diff --git a/tests/build_mpi.sh b/tests/build_mpi.sh
new file mode 100644
index 00000000..464bb395
--- /dev/null
+++ b/tests/build_mpi.sh
@@ -0,0 +1,6 @@
+cd
+mkdir -p build/netgen
+cd build/netgen
+cmake ../../src/netgen -DUSE_CCACHE=ON -DUSE_MPI=ON
+make -j12
+make install
diff --git a/tests/dockerfile_mpi b/tests/dockerfile_mpi
new file mode 100644
index 00000000..ddb7e51b
--- /dev/null
+++ b/tests/dockerfile_mpi
@@ -0,0 +1,5 @@
+FROM ubuntu:18.04
+ENV DEBIAN_FRONTEND=noninteractive
+MAINTAINER Matthias Hochsteger <matthias.hochsteger@tuwien.ac.at>
+RUN apt-get update && apt-get -y install python3 libpython3-dev libxmu-dev tk-dev tcl-dev cmake git g++ libglu1-mesa-dev ccache python3-pytest python3-numpy python3-tk clang-tidy python3-distutils clang libopenmpi-dev openmpi-bin gfortran
+ADD . /root/src/netgen