diff --git a/Common/DataModel/vtkPath.h b/Common/DataModel/vtkPath.h
index 485ab0b5aaf13cfdaf9ef7c128c481d8069aa589..244ca79adc2ad257a08d2c574380f8a9f602f9f6 100644
--- a/Common/DataModel/vtkPath.h
+++ b/Common/DataModel/vtkPath.h
@@ -12,11 +12,11 @@
      PURPOSE.  See the above copyright notice for more information.
 
 =========================================================================*/
-// .NAME vtkPath - concrete dataset representing a path defined by Bezier
+// .NAME vtkPath - concrete dataset representing a path defined by Bézier
 // curves.
 // .SECTION Description
-// vtkPath provides a container for paths composed of line segment and
-// 2nd/3rd order Bezier curves.
+// vtkPath provides a container for paths composed of line segments,
+// 2nd-order (quadratic) and 3rd-order (cubic) Bézier curves.
 
 #ifndef vtkPath_h
 #define vtkPath_h
diff --git a/Filters/Sources/vtkArcSource.cxx b/Filters/Sources/vtkArcSource.cxx
index 2a5912c4003d4a40d87cabdee3bf9574a9c6c0e5..3eec41e417eed75f655b0a995585e3f8c0834d45 100644
--- a/Filters/Sources/vtkArcSource.cxx
+++ b/Filters/Sources/vtkArcSource.cxx
@@ -60,13 +60,15 @@ vtkArcSource::vtkArcSource(int res)
   // Default arc is a quarter-circle
   this->Angle =  90.;
 
-  // Default resolution
+  // Ensure resolution (number of line segments to approximate the arc)
+  // is at least 1
   this->Resolution = (res < 1 ? 1 : res);
 
-  // Default resolution
+  // By default use the shortest angular sector
+  // rather than its complement (a.k.a. negative coterminal)
   this->Negative = false;
 
-  // By default use the original API
+  // By default use the original API (endpoints + center)
   this->UseNormalAndAngle = false;
 
   this->OutputPointsPrecision = SINGLE_PRECISION;
diff --git a/Filters/Sources/vtkArcSource.h b/Filters/Sources/vtkArcSource.h
index 38329383ae1abb179a5312b9cb9058f5168b165b..6ab586248200931f0d8d748d8a287b6e054e6547 100644
--- a/Filters/Sources/vtkArcSource.h
+++ b/Filters/Sources/vtkArcSource.h
@@ -18,8 +18,9 @@
 // endpoints and a center. The number of segments composing the polyline
 // is controlled by setting the object resolution.
 // Alternatively, one can use a better API (that does not allow for
-// inconsistent nor ambiguous inputs), using a starting point (polar vector),
-// a normal to the plane of the arc, and an angle defining the arc length.
+// inconsistent nor ambiguous inputs), using a starting point (polar vector,
+// measured from the arc's center), a normal to the plane of the arc,
+// and an angle defining the arc length.
 // Since the default API remains the original one, in order to use
 // the improved API, one must switch the UseNormalAndAngle flag to TRUE.
 
@@ -91,7 +92,7 @@ public:
   // By default the arc spans the shortest angular sector point1 and point2.
   // By setting this to true, the longest angular sector is used instead
   // (i.e. the negative coterminal angle to the shortest one).
-  // Note: false by default.
+  // Note: This is only used when UseNormalAndAngle is OFF. False by default.
   vtkSetMacro(Negative, bool);
   vtkGetMacro(Negative, bool);
   vtkBooleanMacro(Negative, bool);
diff --git a/Interaction/Style/vtkParallelCoordinatesInteractorStyle.h b/Interaction/Style/vtkParallelCoordinatesInteractorStyle.h
index 6602589d4ff79fb554b2dd1d736acd84a5aa0883..4f2f51a1e4d00c1dddcc288cb03e1629d47d89ab 100644
--- a/Interaction/Style/vtkParallelCoordinatesInteractorStyle.h
+++ b/Interaction/Style/vtkParallelCoordinatesInteractorStyle.h
@@ -20,12 +20,11 @@
 // .NAME vtkParallelCoordinatesInteractorStyle - interactive manipulation of the camera specialized for parallel coordinates
 // .SECTION Description
 // vtkParallelCoordinatesInteractorStyle allows the user to interactively manipulate
-// (rotate, pan, zoomm etc.) the camera.
+// (rotate, pan, zoom etc.) the camera.
 // Several events are overloaded from its superclass
-// vtkParallelCoordinatesInteractorStyle, hence the mouse bindings are
-// different. (The bindings
-// keep the camera's view plane normal perpendicular to the x-y plane.) In
-// summary the mouse events are as follows:
+// vtkInteractorStyleTrackballCamera, hence the mouse bindings are different.
+// (The bindings keep the camera's view plane normal perpendicular to the x-y plane.)
+// In summary, the mouse events are as follows:
 // + Left Mouse button triggers window level events
 // + CTRL Left Mouse spins the camera around its view plane normal
 // + SHIFT Left Mouse pans the camera
diff --git a/Interaction/Widgets/vtkBezierContourLineInterpolator.h b/Interaction/Widgets/vtkBezierContourLineInterpolator.h
index 3745189fee18bb85688e3c1a192ccc6829f86772..27012afc004c6b53ba580d6220743a45d4a271db 100644
--- a/Interaction/Widgets/vtkBezierContourLineInterpolator.h
+++ b/Interaction/Widgets/vtkBezierContourLineInterpolator.h
@@ -15,7 +15,7 @@
 // .NAME vtkBezierContourLineInterpolator - Interpolates supplied nodes with bezier line segments
 // .SECTION Description
 // The line interpolator interpolates supplied nodes (see InterpolateLine)
-// with bezier line segments. The finess of the curve may be controlled using
+// with Bézier line segments. The fitness of the curve may be controlled using
 // SetMaximumCurveError and SetMaximumNumberOfLineSegments.
 //
 // .SECTION See Also
@@ -60,12 +60,12 @@ public:
   vtkGetMacro(MaximumCurveLineSegments, int);
 
   // Description:
-  // Span of the interpolator. ie. the number of control points its supposed
+  // Span of the interpolator, i.e. the number of control points it's supposed
   // to interpolate given a node.
   //
   // The first argument is the current nodeIndex.
-  // ie, you'd be trying to interpolate between nodes "nodeIndex" and
-  // "nodeIndex-1", unless you're closing the contour in which case, you're
+  // i.e., you'd be trying to interpolate between nodes "nodeIndex" and
+  // "nodeIndex-1", unless you're closing the contour, in which case you're
   // trying to interpolate "nodeIndex" and "Node=0". The node span is
   // returned in a vtkIntArray.
   //
diff --git a/Interaction/Widgets/vtkContourLineInterpolator.h b/Interaction/Widgets/vtkContourLineInterpolator.h
index e1b5e6bcd4ce8a88eaa49cb65cda2a64c218fbbf..f29322d281febf7e157cd421e6beda0533877f61 100644
--- a/Interaction/Widgets/vtkContourLineInterpolator.h
+++ b/Interaction/Widgets/vtkContourLineInterpolator.h
@@ -15,18 +15,16 @@
 // .NAME vtkContourLineInterpolator - Defines API for interpolating/modifying nodes from a vtkContourRepresentation
 // .SECTION Description
 // vtkContourLineInterpolator is an abstract base class for interpolators
-// that work are used by the contour representation class to interpolate
+// that are used by the vtkContourRepresentation class to interpolate
 // and/or modify nodes in a contour. Subclasses must override the virtual
-// method: \c InterpolateLine. This is used by the contour representation
+// method \c InterpolateLine. This is used by the contour representation
 // to give the interpolator a chance to define an interpolation scheme
 // between nodes. See vtkBezierContourLineInterpolator for a concrete
-// implementation. Subclasses may also override, \c UpdateNode. This provides
+// implementation. Subclasses may also override \c UpdateNode. This provides
 // a way for the representation to give the interpolator a chance to modify
-// the nodes, as the user constructs the contours. For instance a sticky
+// the nodes, as the user constructs the contours. For instance, a sticky
 // contour widget may be implemented that moves nodes to nearby regions of
-// high gradient, to be used in contour guided segmentation.
-//
-// .SECTION See Also
+// high gradient, to be used in contour-guided segmentation.
 
 #ifndef vtkContourLineInterpolator_h
 #define vtkContourLineInterpolator_h
diff --git a/Interaction/Widgets/vtkContourRepresentation.h b/Interaction/Widgets/vtkContourRepresentation.h
index 8f172f007ef1a343f6425ab77d1fda7042007200..428a54fa5d67a10ecf35e98af0063343432faf3f 100644
--- a/Interaction/Widgets/vtkContourRepresentation.h
+++ b/Interaction/Widgets/vtkContourRepresentation.h
@@ -15,36 +15,37 @@
 // .NAME vtkContourRepresentation - represent the vtkContourWidget
 // .SECTION Description
 // The vtkContourRepresentation is a superclass for various types of
-// representations for the vtkContourWidget.
+// representations for vtkContourWidget.
 //
 // .SECTION Managing contour points
 // The classes vtkContourRepresentationNode, vtkContourRepresentationInternals,
-// vtkContourRepresentationPoint manage the data structure used to represent
+// and vtkContourRepresentationPoint manage the data structure used to represent
 // nodes and points on a contour. A contour may contain several nodes and
-// several more points. Nodes are usually the result of user clicked points on
-// the contour. Additional points are created between nodes to generate a
-// smooth curve using some Interpolator. See the method \c SetLineInterpolator.
+// several additional points. Nodes are usually the result of user-clicked points
+// on the contour. Additional points are created between nodes to generate a
+// smooth curve using some Interpolator -- see the method \c SetLineInterpolator.
+//
 // \par
 // The data structure stores both the world and display positions for every
 // point. (This may seem like a duplication.) The default behaviour of this
 // class is to use the WorldPosition to do all the math. Typically a point is
 // added at a given display position. Its corresponding world position is
-// computed using the point placer and stored. Any query of the display
+// computed using the point placer, and stored. Any query of the display
 // position of a stored point is done via the Renderer, which computes the
 // display position given a world position.
 //
 // \par
-// So why maintain the display position ? Consider drawing a contour on a
+// So why maintain the display position? Consider drawing a contour on a
 // volume widget. You might want the contour to be located at a certain world
 // position in the volume or you might want to be overlayed over the window
 // like an Actor2D. The default behaviour of this class is to provide the
 // former behaviour.
 //
 // \par
-// To achieve the latter behaviour override the methods that return the display
+// To achieve the latter behaviour, override the methods that return the display
 // position (to return the set display position instead of computing it from
 // the world positions) and the method \c BuildLines() to interpolate lines
-// using their display positions intead of world positions.
+// using their display positions instead of world positions.
 //
 // .SECTION See Also
 // vtkContourWidget
@@ -434,11 +435,9 @@ protected:
 
   virtual void BuildLines()=0;
 
-  // This method is called when something changes in the point
-  // placer. It will cause all points to
-  // be updates, and all lines to be regenerated.
-  // Should be extended to detect changes in the line interpolator
-  // too.
+  // This method is called when something changes in the point placer.
+  // It will cause all points to be updated, and all lines to be regenerated.
+  // It should be extended to detect changes in the line interpolator too.
   virtual int  UpdateContour();
   vtkTimeStamp ContourBuildTime;
 
@@ -452,7 +451,7 @@ protected:
   // Description:
   // Build a contour representation from externally supplied PolyData. This
   // is very useful when you use an external program to compute a set of
-  // contour nodes, let's say based on image features. Subsequently, you want
+  // contour nodes (let's say based on image features) and subsequently want
   // to build and display a contour that runs through those points.
   // This method is protected and accessible only from
   // vtkContourWidget::Initialize. The idlist here may be used to initialize
diff --git a/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.cxx b/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.cxx
index f98a47198bd1e8db1f4c565383483d21841a26e3..07dd1aff1dc582a3ba77ee384a9233ea45000dc0 100644
--- a/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.cxx
+++ b/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.cxx
@@ -149,12 +149,12 @@ vtkOrientedGlyphContourRepresentation::vtkOrientedGlyphContourRepresentation()
   this->Mapper = vtkPolyDataMapper::New();
   this->Mapper->SetInputConnection(this->Glypher->GetOutputPort());
 
-  // this turns on resolve coincident topology for everything
+  // This turns on resolve coincident topology for everything
   // as it is a class static on the mapper
   this->Mapper->SetResolveCoincidentTopologyToPolygonOffset();
   this->Mapper->ScalarVisibilityOff();
   this->Mapper->ImmediateModeRenderingOn();
-  // put this on top of other objects
+  // Put this on top of other objects
   this->Mapper->SetRelativeCoincidentTopologyLineOffsetParameters(-1,-1);
   this->Mapper->SetRelativeCoincidentTopologyPolygonOffsetParameters(-1,-1);
   this->Mapper->SetRelativeCoincidentTopologyPointOffsetParameter(-1);
diff --git a/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.h b/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.h
index 133c7820539dbe313e2182b572d9fa9b99bacd16..b07881b0c016170fd7306a5f1b71a88fa725d236 100644
--- a/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.h
+++ b/Interaction/Widgets/vtkOrientedGlyphContourRepresentation.h
@@ -49,7 +49,7 @@ public:
 
   // Description:
   // Specify the cursor shape. Keep in mind that the shape will be
-  // aligned with the  constraining plane by orienting it such that
+  // aligned with the constraining plane by orienting it such that
   // the x axis of the geometry lies along the normal of the plane.
   void SetCursorShape(vtkPolyData *cursorShape);
   vtkPolyData *GetCursorShape();
diff --git a/Utilities/Doxygen/doc_readme.txt b/Utilities/Doxygen/doc_readme.txt
index 100ea0e701323d91bdcdc053a6549eb58fbf993d..3a10b9292dea2a58259bc7e403b9c528bc99e819 100644
--- a/Utilities/Doxygen/doc_readme.txt
+++ b/Utilities/Doxygen/doc_readme.txt
@@ -28,7 +28,7 @@ process. Thus, you might browse or download a pre-built documentation here:
 Nevertheless, Doxygen might still be useful to generate additional
 PDF, Postscript or plain LaTeX output.
 
-This package is made of he following Perl scripts:
+This package is made of the following Perl scripts:
 
 - doc_header2doxygen.pl: convert the VTK headers to the Doxygen format
 - doc_version.pl: extract the VTK version and add it to the documentation set
diff --git a/Views/Context2D/vtkContextInteractorStyle.h b/Views/Context2D/vtkContextInteractorStyle.h
index 97b748ac5ee0a1161e6fdecc7ab42cf6bcac59f1..558c791a6b4659c7f54cc8eabd106b783807cd4b 100644
--- a/Views/Context2D/vtkContextInteractorStyle.h
+++ b/Views/Context2D/vtkContextInteractorStyle.h
@@ -12,12 +12,12 @@
      PURPOSE.  See the above copyright notice for more information.
 
 =========================================================================*/
-// .NAME vtkContextInteractorStyle - An interactor for chart views
+// .NAME vtkContextInteractorStyle - An interactor for chart views.
+//
+// .SECTION Description
 // It observes the user events (mouse events) and propagates them
 // to the scene. If the scene doesn't eat the event, it is propagated
 // to the interactor style superclass.
-//
-// .SECTION Description
 
 #ifndef vtkContextInteractorStyle_h
 #define vtkContextInteractorStyle_h