diff --git a/doc/ng4.tex b/doc/ng4.tex
index bf8db42f..d7d7da39 100644
--- a/doc/ng4.tex
+++ b/doc/ng4.tex
@@ -234,7 +234,7 @@ solid cubeball = orthobrick (0, 0, 0; 1, 1, 1)
         or sphere (0, 0, 0; 0.5) -maxh=0.2;
 \end{verbatim}
 \end{quote}
-The flag {\tt -maxh=0.2} assignes the maximal mesh size of $0.2$ to
+The flag {\tt -maxh=0.2} assigns the maximal mesh size of $0.2$ to
 the solid. The current version, NG4.1, uses the mesh size assigned to
 the main solid of the top-level-object for the domain. Future version
 will contain more possibilities to define mesh-sizes for parts of a
@@ -261,7 +261,7 @@ amount of red, green and blue (RGB) values. The flag {\tt
 
 
 It is possible to specify bounday condition numbers for individual
-surfaces of a solid. The flag {\tt -bc} assignes the bc to all 
+surfaces of a solid. The flag {\tt -bc} assigns the bc to all 
 surfaces of that solid-tree. If several flags are given the one closest
 to the leaves of the tree dominates. The following file defines a 
 cube, with $bc=1$ at the bottom, $bc=2$ at the top, and $bc=3$ for 
@@ -723,7 +723,7 @@ can run netgen in batch-mode using command line arguments.
 Command line arguments are specified as {\it -flag=value}.
 \begin{itemize}
 \item -help \newline
-Prints the availabel command line arguments
+Prints the available command line arguments
 \item -geofile=filename \newline
 Specifies geometry file. Is equivalent to {\it filename}, i.e., you can
 scip {\it -geofile=}.
diff --git a/libsrc/general/bitarray.hpp b/libsrc/general/bitarray.hpp
index 64a4ee6e..ce0ba348 100644
--- a/libsrc/general/bitarray.hpp
+++ b/libsrc/general/bitarray.hpp
@@ -18,7 +18,7 @@ namespace netgen
    
    BitArray is a compressed array of Boolean information. By Set and Clear
    the whole array or one bit can be set or reset, respectively. 
-   Test returns the state of the accoring bit.
+   Test returns the state of the occurring bit.
    No range checking is done.
 
    index ranges from 0 to size-1
@@ -152,7 +152,7 @@ int BitArray :: Test (INDEX i) const
    
    BitArray is an array of Boolean information. By Set and Clear
    the whole array or one bit can be set or reset, respectively. 
-   Test returns the state of the accoring bit.
+   Test returns the state of the occurring bit.
    No range checking is done.
 */
 template <int BASE = 1>
diff --git a/libsrc/general/hashtabl.cpp b/libsrc/general/hashtabl.cpp
index a9ef002c..30f6ed1f 100644
--- a/libsrc/general/hashtabl.cpp
+++ b/libsrc/general/hashtabl.cpp
@@ -95,7 +95,7 @@ namespace netgen
     ost << "Hashtable: " << endl
 	<< "size             : " << n << endl
 	<< "elements per row : " << (double(sumn) / double(n)) << endl
-	<< "av. acces time   : " 
+	<< "av. access time  : " 
 	<< (sumn ? (double (sumnn) / double(sumn)) : 0) << endl;
   }
 
diff --git a/libsrc/general/hashtabl.hpp b/libsrc/general/hashtabl.hpp
index cc550bf7..2ff83821 100644
--- a/libsrc/general/hashtabl.hpp
+++ b/libsrc/general/hashtabl.hpp
@@ -515,7 +515,7 @@ public:
 
 
 
-  // returns 1, if new postion is created
+  // returns 1, if new position is created
   int PositionCreate (const INDEX & ind, int & apos)
   {
     int i = HashValue (ind);
@@ -677,7 +677,7 @@ public:
       }
   }
 
-  // returns 1, if new postion is created
+  // returns 1, if new position is created
   bool PositionCreate0 (const INDEX_2 & ind, int & apos)
   {
     int i = HashValue (ind);
@@ -875,7 +875,7 @@ public:
 
 
   
-  // returns true, if new postion is created
+  // returns true, if new position is created
   bool PositionCreate (const INDEX_3 & ind, int & apos)
   {
     int i = HashValue (ind);
diff --git a/libsrc/general/mystring.cpp b/libsrc/general/mystring.cpp
index dc59c80e..279a197b 100644
--- a/libsrc/general/mystring.cpp
+++ b/libsrc/general/mystring.cpp
@@ -5,7 +5,7 @@
 //
 // project:              doctoral thesis
 //
-// autor:                Dipl.-Ing. Gerstmayr Johannes
+// author:               Dipl.-Ing. Gerstmayr Johannes
 //
 // generated:            20.12.98
 // last change:          20.12.98
diff --git a/libsrc/general/mystring.hpp b/libsrc/general/mystring.hpp
index af522fc8..75655362 100644
--- a/libsrc/general/mystring.hpp
+++ b/libsrc/general/mystring.hpp
@@ -5,7 +5,7 @@
 //
 // project:              doctoral thesis, program smart
 //
-// autor:                Dipl.-Ing. Gerstmayr Johannes
+// author:               Dipl.-Ing. Gerstmayr Johannes
 //
 // generated:            20.12.98
 // last change:          20.12.98
diff --git a/libsrc/include/incopengl.hpp b/libsrc/include/incopengl.hpp
index b060f67c..b3fcc71b 100644
--- a/libsrc/include/incopengl.hpp
+++ b/libsrc/include/incopengl.hpp
@@ -22,7 +22,7 @@
 
 #ifdef WIN32
 // part of OpenGL 1.2, but not in Microsoft's OpenGL 1.1 header:
-// GL version sould be checked at runtime
+// GL version should be checked at runtime
 #define GL_CLAMP_TO_EDGE                  0x812F
 #define GL_ARRAY_BUFFER                   0x8892
 #define GL_ELEMENT_ARRAY_BUFFER           0x8893
diff --git a/libsrc/include/nginterface.h b/libsrc/include/nginterface.h
index 4bce5914..3ddf24b8 100644
--- a/libsrc/include/nginterface.h
+++ b/libsrc/include/nginterface.h
@@ -58,7 +58,7 @@ typedef int NG_FACE[4];      // points, last one is 0 for trig
 extern "C" {
 #endif
   
-  // load geomtry from file 
+  // load geometry from file 
   DLL_HEADER void Ng_LoadGeometry (const char * filename);
   
   // load netgen mesh
@@ -149,12 +149,12 @@ extern "C" {
                                                const int * const indices = NULL, const int numind = 0);
   
 
-  // is elment ei curved ?
+  // is element ei curved ?
   DLL_HEADER int Ng_IsElementCurved (int ei);
-  // is elment sei curved ?
+  // is element sei curved ?
   DLL_HEADER int Ng_IsSurfaceElementCurved (int sei);
 
-  /// Curved Elemens:
+  /// Curved Elements:
   /// xi..local coordinates
   /// x ..global coordinates
   /// dxdxi...D x D Jacobian matrix (row major storage)
@@ -169,7 +169,7 @@ extern "C" {
   
 
 
-  /// Curved Elemens:
+  /// Curved Elements:
   /// xi..local coordinates
   /// x ..global coordinates
   /// dxdxi...D x D-1 Jacobian matrix (row major storage)
@@ -177,7 +177,7 @@ extern "C" {
   DLL_HEADER void Ng_GetSurfaceElementTransformation (int sei, const double * xi, 
                                                       double * x, double * dxdxi);
   
-  /// Curved Elemens:
+  /// Curved Elements:
   /// xi..local coordinates
   /// sxi..step xi
   /// x ..global coordinates
@@ -281,7 +281,7 @@ extern "C" {
 
 #ifdef PARALLEL
 
-  // the folling functions are 0-base  !!
+  // the following functions are 0-base  !!
 
   // number on distant processor 
   // returns pairs  (dist_proc, num_on_dist_proc)
diff --git a/libsrc/meshing/boundarylayer.cpp b/libsrc/meshing/boundarylayer.cpp
index 5749268c..ab424dff 100644
--- a/libsrc/meshing/boundarylayer.cpp
+++ b/libsrc/meshing/boundarylayer.cpp
@@ -283,7 +283,7 @@ namespace netgen
 
 
          // Add quad surface elements at edges for surfaces which 
-         // dont have boundary layers
+         // don't have boundary layers
 
          // Bit array to keep track of segments already processed
          BitArray segsel(nseg);
diff --git a/libsrc/meshing/hprefinement.cpp b/libsrc/meshing/hprefinement.cpp
index 97285259..1f257b48 100644
--- a/libsrc/meshing/hprefinement.cpp
+++ b/libsrc/meshing/hprefinement.cpp
@@ -1968,7 +1968,7 @@ bool CheckSingularities(Mesh & mesh, INDEX_2_HASHTABLE<int> & edges, INDEX_2_HAS
 
     for (int i = 0; i < misses.Size(); i++)
       if (misses[i])
-	cout << " in update classification missing case " << i << " occured " << misses[i] << " times" << endl;
+	cout << " in update classification missing case " << i << " occurred " << misses[i] << " times" << endl;
 
     return(sing); 
   }
diff --git a/libsrc/meshing/hprefinement.hpp b/libsrc/meshing/hprefinement.hpp
index 7554fec0..8ccf5069 100644
--- a/libsrc/meshing/hprefinement.hpp
+++ b/libsrc/meshing/hprefinement.hpp
@@ -118,7 +118,7 @@ enum HPREF_ELEMENT_TYPE {
   HP_TET_1E_4V,     // V1,2,3,4
 
 
-  // 2 connected edges, additonally marked Vs
+  // 2 connected edges, additionally marked Vs
   HP_TET_2EA_0V = 220,    // E1-2, E1-3
   HP_TET_2EA_1VA,   // V2
   HP_TET_2EA_1VB,   // V3
diff --git a/libsrc/meshing/improve2.cpp b/libsrc/meshing/improve2.cpp
index e11338ba..97fcb764 100644
--- a/libsrc/meshing/improve2.cpp
+++ b/libsrc/meshing/improve2.cpp
@@ -814,8 +814,8 @@ namespace netgen
     Vec3d n, ng;
     Array<Vec3d> ngs(3);
 
-    (*mycout) << "Check Surface Approxiamtion" << endl;
-    (*testout) << "Check Surface Approxiamtion" << endl;
+    (*mycout) << "Check Surface Approximation" << endl;
+    (*testout) << "Check Surface Approximation" << endl;
 
     for (i = 1; i <= ne; i++)
     {
diff --git a/libsrc/meshing/meshclass.cpp b/libsrc/meshing/meshclass.cpp
index 1209561c..3939c4f2 100644
--- a/libsrc/meshing/meshclass.cpp
+++ b/libsrc/meshing/meshclass.cpp
@@ -1598,7 +1598,7 @@ namespace netgen
               }
           }
         else 
-          cerr << "illegal elemenet for buildboundaryedges" << endl;
+          cerr << "illegal element for buildboundaryedges" << endl;
       }
 
 
@@ -3270,7 +3270,7 @@ namespace netgen
 
 
     /*
-    // compress points doesnt work for identified points !
+    // compress points doesn't work for identified points !
     if (identifiedpoints)
     {
     for (i = 1; i <= identifiedpoints->GetNBags(); i++)
diff --git a/libsrc/meshing/meshfunc.cpp b/libsrc/meshing/meshfunc.cpp
index 104c6966..75f761b4 100644
--- a/libsrc/meshing/meshfunc.cpp
+++ b/libsrc/meshing/meshfunc.cpp
@@ -584,7 +584,7 @@ namespace netgen
     if (res)
       {
 	mesh3d.FindOpenElements();
-	PrintSysError (1, "Open elemetns: ", mesh3d.GetNOpenElements());
+	PrintSysError (1, "Open elements: ", mesh3d.GetNOpenElements());
 	exit (1);
       }
 
diff --git a/libsrc/meshing/meshtype.hpp b/libsrc/meshing/meshtype.hpp
index 8f04a2f8..a2424427 100644
--- a/libsrc/meshing/meshtype.hpp
+++ b/libsrc/meshing/meshtype.hpp
@@ -748,7 +748,7 @@ namespace netgen
 
     ///
     void GetBox (const T_POINTS & points, Box3d & box) const;
-    /// Calculates Volume of elemenet
+    /// Calculates Volume of element
     double Volume (const T_POINTS & points) const;
     ///
     DLL_HEADER void Print (ostream & ost) const;
@@ -1162,7 +1162,7 @@ namespace netgen
     int checkoverlappingboundary = 1;
     /// check chart boundary (sometimes too restrictive)
     int checkchartboundary = 1;
-    /// safty factor for curvatures (elemetns per radius)
+    /// safety factor for curvatures (elements per radius)
     double curvaturesafety = 2;
     /// minimal number of segments per edge
     double segmentsperedge = 1;
diff --git a/ng/nghelp.tcl b/ng/nghelp.tcl
index 7c1422cd..809e1912 100644
--- a/ng/nghelp.tcl
+++ b/ng/nghelp.tcl
@@ -154,7 +154,7 @@ set_menu_help "Check Volume Mesh" "Checks conformity of volume mesh."
 set_menu_help "Edit Boundary Conditions" "Open dialog for setting boundary condition numbers for individual faces."
 set_menu_help "Analyze Geometry" "Perform only first step in mesh generation. Action depends on geometry type, e.g. generates charts for STL mesh, find vertices in CSG geometries."
 set_menu_help "Mesh Edges" "Meshes edges"
-set_menu_help "Mesh Surface" "Generates surface mesh. Includes already surface optimization for some geomtry types."
+set_menu_help "Mesh Surface" "Generates surface mesh. Includes already surface optimization for some geometry types."
 set_menu_help "Optimize Surface" "Optimizes surface mesh."
 set_menu_help "Surface Optim. Step" "Performs a specific surface optimiztion step. Mesh smoothing moves nodes. edge swapping swaps the diagonal of a quadrilateral built by two triangles, criterion either by number of nodes, or anlges. Combine points eliminates triangles by combining points (in the center of gravity)."
 set_menu_help "Mesh Volume" "Performs volume meshing. Algorithm is a combination of Delaunay and Rule-based Advancing Front"
@@ -183,7 +183,7 @@ set_menu_help "MS from Surf Mesh" "Defines mesh-size by the surface mesh."
 set f .options_dlg.nb.nbframe.general
 # set_control_help $f "General meshing page"
 set_control_help $f.fine "Controls relative mesh size.\nThis control affects other mesh-size controls in common"
-set_control_help $f.first "First step in mesh generation. Usually, meshing  starts from \"analyze geometry\". If the surface mesh is already available \"First step\" should be set to \"mesh volume\""
+set_control_help $f.first "First step in mesh generation. Usually, meshing starts from \"analyze geometry\". If the surface mesh is already available \"First step\" should be set to \"mesh volume\""
 set_control_help $f.last "Last step in mesh generation. If only the surface mesh is required, please set \"Last Step\" to \"Optimize Surface\""
 
 set_control_help .bubar.surfm "Start mesh generation"
diff --git a/ng/onetcl.cpp b/ng/onetcl.cpp
index 9f3caf2a..3a5987cc 100644
--- a/ng/onetcl.cpp
+++ b/ng/onetcl.cpp
@@ -4327,7 +4327,7 @@ const char * ngscript[] = {""
 ,"set_menu_help \"Edit Boundary Conditions\" \"Open dialog for setting boundary condition numbers for individual faces.\"\n"
 ,"set_menu_help \"Analyze Geometry\" \"Perform only first step in mesh generation. Action depends on geometry type, e.g. generates charts for STL mesh, find vertices in CSG geometries.\"\n"
 ,"set_menu_help \"Mesh Edges\" \"Meshes edges\"\n"
-,"set_menu_help \"Mesh Surface\" \"Generates surface mesh. Includes already surface optimization for some geomtry types.\"\n"
+,"set_menu_help \"Mesh Surface\" \"Generates surface mesh. Includes already surface optimization for some geometry types.\"\n"
 ,"set_menu_help \"Optimize Surface\" \"Optimizes surface mesh.\"\n"
 ,"set_menu_help \"Surface Optim. Step\" \"Performs a specific surface optimiztion step. Mesh smoothing moves nodes. edge swapping swaps the diagonal of a quadrilateral built by two triangles, criterion either by number of nodes, or anlges. Combine points eliminates triangles by combining points (in the center of gravity).\"\n"
 ,"set_menu_help \"Mesh Volume\" \"Performs volume meshing. Algorithm is a combination of Delaunay and Rule-based Advancing Front\"\n"
@@ -4349,7 +4349,7 @@ const char * ngscript[] = {""
 ,"set_menu_help \"MS from Surf Mesh\" \"Defines mesh-size by the surface mesh.\"\n"
 ,"set f .options_dlg.nb.nbframe.general\n"
 ,"set_control_help $f.fine \"Controls relative mesh size.\\nThis control affects other mesh-size controls in common\"\n"
-,"set_control_help $f.first \"First step in mesh generation. Usually, meshing  starts from \\\"analyze geometry\\\". If the surface mesh is already available \\\"First step\\\" should be set to \\\"mesh volume\\\"\"\n"
+,"set_control_help $f.first \"First step in mesh generation. Usually, meshing starts from \\\"analyze geometry\\\". If the surface mesh is already available \\\"First step\\\" should be set to \\\"mesh volume\\\"\"\n"
 ,"set_control_help $f.last \"Last step in mesh generation. If only the surface mesh is required, please set \\\"Last Step\\\" to \\\"Optimize Surface\\\"\"\n"
 ,"set_control_help .bubar.surfm \"Start mesh generation\"\n"
 ,"set_control_help .bubar.stopm \"Stop mesh generation\"\n"