Fixes a bunch of typos in comments.

29 files changed, 87 insertions, 87 deletions

diff --git a/FL/Enumerations.H b/FL/Enumerations.H
index 914fc6a56..178c561c3 100644
--- a/FL/Enumerations.H
+++ b/FL/Enumerations.H
@@ -415,7 +415,7 @@ enum Fl_Event { // events
 /**@{*/
 /** These constants determine when a callback is performed.
 
-    Fl_When is a bit field. Some values are merely shorcuts for common bit
+    Fl_When is a bit field. Some values are merely shortcuts for common bit
     combinations. New flags may be added in the future, so it's important to
     mask the required bit when reading via \p when().
 
@@ -1059,9 +1059,9 @@ const Fl_Font FL_SCREEN_BOLD            = 14;   ///< Default monospaced bold scr
 const Fl_Font FL_ZAPF_DINGBATS          = 15;   ///< Zapf-dingbats font
 
 const Fl_Font FL_FREE_FONT              = 16;   ///< first one to allocate
-const Fl_Font FL_BOLD                   = 1;    ///< add this to helvetica, courier, or times
-const Fl_Font FL_ITALIC                 = 2;    ///< add this to helvetica, courier, or times
-const Fl_Font FL_BOLD_ITALIC            = 3;    ///< add this to helvetica, courier, or times
+const Fl_Font FL_BOLD                   = 1;    ///< add this to Helvetica, Courier, or Times
+const Fl_Font FL_ITALIC                 = 2;    ///< add this to Helvetica, Courier, or Times
+const Fl_Font FL_BOLD_ITALIC            = 3;    ///< add this to Helvetica, Courier, or Times
 
 /**@}*/
 
diff --git a/FL/Fl.H b/FL/Fl.H
index c10551db5..25d5dcabd 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -1162,7 +1162,7 @@ public:
     that the normal one is first, followed by bold, italic, and bold
     italic.
 
-    The only argument to this function is somehat obsolete since FLTK and most
+    The only argument to this function is somewhat obsolete since FLTK and most
     underlying operating systems move to support Unicode. For completeness,
     following is the original documentation and a few updates:
 
diff --git a/FL/Fl_Anim_GIF_Image.H b/FL/Fl_Anim_GIF_Image.H
index a23ad2a5f..ca1c445ce 100644
--- a/FL/Fl_Anim_GIF_Image.H
+++ b/FL/Fl_Anim_GIF_Image.H
@@ -1,7 +1,7 @@
 //
 // Fl_Anim_GIF_Image class header for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2016-2022 by Christian Grabner <wcout@gmx.net>.
+// Copyright 2016-2023 by Christian Grabner <wcout@gmx.net>.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -23,7 +23,7 @@ class Fl_Widget;
 
 #include <FL/Fl_GIF_Image.H>
 
-// Load and display animater GIF images
+// Load and display animated GIF images
 class FL_EXPORT Fl_Anim_GIF_Image : public Fl_GIF_Image {
 
   class FrameInfo; // internal helper class
@@ -62,7 +62,7 @@ public:
      by storing frame data not as canvas-sized images but use the
      sizes defined in the GIF file.
      The drawbacks are higher cpu usage during playback and maybe
-     minor artefacts when resized.
+     minor artifacts when resized.
      */
     OPTIMIZE_MEMORY = 8,
     /**
diff --git a/FL/Fl_Browser.H b/FL/Fl_Browser.H
index 5b86a6599..f1e1009a9 100644
--- a/FL/Fl_Browser.H
+++ b/FL/Fl_Browser.H
@@ -1,7 +1,7 @@
 //
 // Browser header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -230,7 +230,7 @@ public:
     \li <tt>'\@c'</tt> Center the line horizontally
     \li <tt>'\@r'</tt> Right-justify the text
     \li <tt>'\@N'</tt> Use fl_inactive_color() to draw the text
-    \li <tt>'\@B0', '\@B1', ... '\@B255'</tt> Fill the backgound with
+    \li <tt>'\@B0', '\@B1', ... '\@B255'</tt> Fill the background with
       fl_color(n)
     \li <tt>'\@C0', '\@C1', ... '\@C255'</tt> Use fl_color(n) to draw the text
     \li <tt>'\@F0', '\@F1', ...</tt> Use fl_font(n) to draw the text
diff --git a/FL/Fl_Copy_Surface.H b/FL/Fl_Copy_Surface.H
index 752179a01..c9e74e259 100644
--- a/FL/Fl_Copy_Surface.H
+++ b/FL/Fl_Copy_Surface.H
@@ -1,7 +1,7 @@
 //
 // Copy-to-clipboard code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2014 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -94,7 +94,7 @@ protected:
   int printable_rect(int *w, int *h) FL_OVERRIDE;
   /** Each platform implements this function its own way.
    It returns an object implementing all virtual functions
-   of class Fl_Copy_Surface_Driver for the plaform.
+   of class Fl_Copy_Surface_Driver for the platform.
    */
   static Fl_Copy_Surface_Driver *newCopySurfaceDriver(int w, int h);
 };
diff --git a/FL/Fl_GIF_Image.H b/FL/Fl_GIF_Image.H
index f1f31724e..e6994e688 100644
--- a/FL/Fl_GIF_Image.H
+++ b/FL/Fl_GIF_Image.H
@@ -1,7 +1,7 @@
 //
 // GIF image header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -45,7 +45,7 @@ public:
 
 protected:
 
-  // Proteced constructors needed for animated GIF support through Fl_Anim_GIF_Image.
+  // Protected constructors needed for animated GIF support through Fl_Anim_GIF_Image.
   Fl_GIF_Image(const char* filename, bool anim);
   Fl_GIF_Image(const char* imagename, const unsigned char *data, const size_t length, bool anim);
   // Protected default constructor needed for Fl_Anim_GIF_Image.
diff --git a/FL/Fl_Gl_Window.H b/FL/Fl_Gl_Window.H
index 8889a086b..65c7a5a9d 100644
--- a/FL/Fl_Gl_Window.H
+++ b/FL/Fl_Gl_Window.H
@@ -1,7 +1,7 @@
 //
 // OpenGL header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -135,12 +135,12 @@ public:
   static int can_do(const int *m) {return can_do(0, m);}
   /**  Returns non-zero if the hardware supports the current OpenGL mode. */
   int can_do() {return can_do(mode_,alist);}
-  /** Returns the current OpenGL capabilites of the window.
+  /** Returns the current OpenGL capabilities of the window.
    Don't use this if capabilities were set through Fl_Gl_Window::mode(const int *a).
    */
   Fl_Mode mode() const {return (Fl_Mode)mode_;}
   /**
-   Set or change the OpenGL capabilites of the window.  The value can be
+   Set or change the OpenGL capabilities of the window.  The value can be
    any of the following OR'd together:
 
    - \c FL_RGB - RGB color (not indexed)
@@ -180,7 +180,7 @@ public:
    \version the <tt>FL_OPENGL3</tt> flag appeared in version 1.3.4
    */
   int mode(int a) {return mode(a,0);}
-  /** Set the OpenGL capabilites of the window using platform-specific data.
+  /** Set the OpenGL capabilities of the window using platform-specific data.
    \param a zero-ending array of platform-specific attributes and attribute values
    <p><b>Unix/Linux platform</b>: attributes are GLX attributes adequate for the 3rd argument of
    the <tt>glXChooseVisual()</tt> function (e.g., <tt>GLX_DOUBLEBUFFER</tt>, defined by including <GL/glx.h>).
diff --git a/FL/Fl_PNG_Image.H b/FL/Fl_PNG_Image.H
index 1b5e32179..41b9de5df 100644
--- a/FL/Fl_PNG_Image.H
+++ b/FL/Fl_PNG_Image.H
@@ -1,7 +1,7 @@
 //
 // PNG image header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -24,7 +24,7 @@
 /**
   The Fl_PNG_Image class supports loading, caching,
   and drawing of Portable Network Graphics (PNG) image files. The
-  class loads colormapped and full-color images and handles color-
+  class loads color-mapped and full-color images and handles color-
   and alpha-based transparency.
 */
 class FL_EXPORT Fl_PNG_Image : public Fl_RGB_Image {
diff --git a/FL/Fl_Plugin.H b/FL/Fl_Plugin.H
index aca8d4b8b..1806f025b 100644
--- a/FL/Fl_Plugin.H
+++ b/FL/Fl_Plugin.H
@@ -1,7 +1,7 @@
 //
 // A Plugin system for FLTK, implemented in Fl_Preferences.cxx.
 //
-// Copyright 2002-2010 by Matthias Melcher.
+// Copyright 2002-2023 by Matthias Melcher.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -30,7 +30,7 @@
  linking C++ classes at run-time, or optionally linking modules at compile
  time without the need to change the main application.
 
- Fl_Plugin_Manager uses static initialisation to create the plugin interface
+ Fl_Plugin_Manager uses static initialization to create the plugin interface
  early during startup. Plugins are stored in a temporary database, organized
  in classes.
 
diff --git a/FL/Fl_Preferences.H b/FL/Fl_Preferences.H
index a74be23eb..5f988a344 100644
--- a/FL/Fl_Preferences.H
+++ b/FL/Fl_Preferences.H
@@ -29,7 +29,7 @@ class Fl_String;
  \brief Fl_Preferences store user settings between application starts.
 
  Fl_Preferences are similar to the Registry on Windows and Preferences on MacOS,
- providing a simple method to store customisable user settings between app
+ providing a simple method to store customizable user settings between app
  launches, for instance the previous window position or a history of previously
  used documents.
 
diff --git a/FL/Fl_Rect.H b/FL/Fl_Rect.H
index 0de6dfcb2..29e7fd451 100644
--- a/FL/Fl_Rect.H
+++ b/FL/Fl_Rect.H
@@ -1,7 +1,7 @@
 //
 // Fl_Rect header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -22,7 +22,7 @@
 /**
   Rectangle with standard FLTK coordinates (X, Y, W, H).
 
-  This may be used internally, for overloaded widget contructors and other
+  This may be used internally, for overloaded widget constructors and other
   overloaded methods like fl_measure(), fl_text_extents(), fl_rect(),
   fl_rectf(), and maybe more.
 */
diff --git a/FL/Fl_Roller.H b/FL/Fl_Roller.H
index 5775058b8..dc9aa4381 100644
--- a/FL/Fl_Roller.H
+++ b/FL/Fl_Roller.H
@@ -1,7 +1,7 @@
 //
 // Roller header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -30,7 +30,7 @@
 
   The roller can be controlled by clicking and dragging the mouse, by the
   corresponding arrow keys when the roller has the keyboard focus, or by the
-  mousewheels when the mouse pointer is positioned over the roller widget.
+  mouse wheels when the mouse pointer is positioned over the roller widget.
 
   \image html Fl_Roller.png
   \image latex Fl_Roller.png "Fl_Roller" width=4cm
diff --git a/FL/Fl_String.H b/FL/Fl_String.H
index f3ae71b1b..e0280f43c 100644
--- a/FL/Fl_String.H
+++ b/FL/Fl_String.H
@@ -1,7 +1,7 @@
 //
 // Basic Fl_String header for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2021-2022 by Bill Spitzak and others.
+// Copyright 2021-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -34,7 +34,7 @@
   a drop-in if we ever decide to allow templates and the std library.
 
   Fl_String always maintains a trailing \e nul byte, but can also contain
-  \e nul bytes insde the string if the constructor
+  \e nul bytes inside the string if the constructor
   Fl_String(const char *str, int size) is used.
 
   Assignment and copy constructors \b copy the string value such that the
@@ -55,7 +55,7 @@ class FL_EXPORT Fl_String {
 
 private:
   /*
-   FLTK does no small string optimisation.
+   FLTK does no small string optimization.
    If the string is empty and capacity is not set, buffer_ will be NULL.
    */
   char *buffer_;
diff --git a/FL/Fl_Text_Buffer.H b/FL/Fl_Text_Buffer.H
index ac0221b5c..fa3916eba 100644
--- a/FL/Fl_Text_Buffer.H
+++ b/FL/Fl_Text_Buffer.H
@@ -40,7 +40,7 @@
 /*
  "character size" is the size of a UTF-8 character in bytes
  "character width" is the width of a Unicode character in pixels
- "column" was orginally defined as a character offset from the left margin.
+ "column" was originally defined as a character offset from the left margin.
  It was identical to the byte offset. In UTF-8, we have neither a byte offset
  nor truly fixed width fonts (*). Column could be a pixel value multiplied with
  an average character width (which is a bearable approximation).
@@ -192,7 +192,7 @@ typedef void (*Fl_Text_Predelete_Cb)(int pos, int nDeleted, void* cbArg);
  All text in Fl_Text_Buffer must be encoded in UTF-8. All indices used in the
  function calls must be aligned to the start of a UTF-8 sequence. All indices
  and pointers returned will be aligned. All functions that return a single
- character will return that in an unsiged int in UCS-4 encoding.
+ character will return that in an unsigned int in UCS-4 encoding.
 
  The Fl_Text_Buffer class is used by the Fl_Text_Display and Fl_Text_Editor
  to manage complex text data and is based upon the excellent NEdit text
@@ -331,7 +331,7 @@ public:
   int undo(int *cp=0);
 
   /**
-   Check if undo is anabled and if the last action can be undone.
+   Check if undo is enabled and if the last action can be undone.
    \see canUndo()
    */
   bool can_undo() const;
@@ -342,7 +342,7 @@ public:
   int redo(int *cp=0);
 
   /**
-   Check if undo is anabled and if the last undo action can be redone.
+   Check if undo is enabled and if the last undo action can be redone.
    \see canUndo()
    */
   bool can_redo() const;
diff --git a/FL/fl_draw.H b/FL/fl_draw.H
index 7f46a80f7..758f8082d 100644
--- a/FL/fl_draw.H
+++ b/FL/fl_draw.H
@@ -40,7 +40,7 @@ FL_EXPORT extern char fl_draw_shortcut;
 // Colors:
 /**
   Set the color for all subsequent drawing operations.
-  For colormapped displays, a color cell will be allocated out of
+  For color-mapped displays, a color cell will be allocated out of
   \p fl_colormap the first time you use a color. If the colormap fills up
   then a least-squares algorithm is used to find the closest color.
   If no valid graphical context (fl_gc) is available,
@@ -871,7 +871,7 @@ inline void fl_text_extents(const char *t, int n, int &dx, int &dy, int &w, int
 }
 
 // font encoding:
-// Note: doxygen comments here to avoid duplication for os-sepecific cases
+// Note: doxygen comments here to avoid duplication for os-specific cases
 /**
   Convert text from Windows/X11 latin1 character set to local encoding.
   \param[in] t character string (latin1 encoding)
diff --git a/fluid/CodeEditor.cxx b/fluid/CodeEditor.cxx
index 40fe667fc..119090628 100644
--- a/fluid/CodeEditor.cxx
+++ b/fluid/CodeEditor.cxx
@@ -2,7 +2,7 @@
 // Code editor widget for the Fast Light Tool Kit (FLTK).
 // Syntax highlighting rewritten by erco@seriss.com 09/15/20.
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -118,7 +118,7 @@ void CodeEditor::style_unfinished_cb(int, void*) {
  \param[in] pos insert position in text
  \param[in] nInserted number of bytes inserted
  \param[in] nDeleted number of bytes deleted
- \param[in] cbArg pointer back to the code editr
+ \param[in] cbArg pointer back to the code editor
  */
 void CodeEditor::style_update(int pos, int nInserted, int nDeleted,
                               int /*nRestyled*/, const char * /*deletedText*/,
@@ -248,13 +248,13 @@ CodeEditor::~CodeEditor() {
 }
 
 /**
- Attempt to make the fluid code editor widget honour textsize setting.
+ Attempt to make the fluid code editor widget honor textsize setting.
  This works by updating the fontsizes in the style table.
  \param[in] s the new general height of the text font
  */
 void CodeEditor::textsize(Fl_Fontsize s) {
   Fl_Text_Editor::textsize(s); // call base class method
-  // now attempt to update our styletable to honour the new size...
+  // now attempt to update our styletable to honor the new size...
   int entries = sizeof(styletable) / sizeof(styletable[0]);
   for(int iter = 0; iter < entries; iter++) {
     styletable[iter].size = s;
diff --git a/fluid/ExternalCodeEditor_UNIX.cxx b/fluid/ExternalCodeEditor_UNIX.cxx
index a669d8188..a04416034 100644
--- a/fluid/ExternalCodeEditor_UNIX.cxx
+++ b/fluid/ExternalCodeEditor_UNIX.cxx
@@ -45,7 +45,7 @@ static int is_dir(const char *dirname) {
 /** \class ExternalCodeEditor
  Support for an external C++ code editor for Fluid Code block.
 
- This class can launch and quit a user defined program for editiing
+ This class can launch and quit a user defined program for editing
  code outside of Fluid.
  It observes changes in the external file and updates the Fluid
  widget to stay synchronized.
@@ -561,7 +561,7 @@ void ExternalCodeEditor::alert_pipe_cb(FL_SOCKET s, void* d) {
     return;
   const char* cmd = self->command_line_.c_str();
   if (cmd && *cmd) {
-    if (cmd[0] == '/') { // is this an absoluet filename?
+    if (cmd[0] == '/') { // is this an absolute filename?
       fl_alert("Can't launch external editor '%s':\n%s\n\ncmd: \"%s\"",
                fl_filename_name(cmd), strerror(self->last_error_), cmd);
     } else {
diff --git a/fluid/Fd_Snap_Action.cxx b/fluid/Fd_Snap_Action.cxx
index e6949e68d..401ae856f 100644
--- a/fluid/Fd_Snap_Action.cxx
+++ b/fluid/Fd_Snap_Action.cxx
@@ -29,7 +29,7 @@
 
 // TODO: warning if the user wants to change builtin layouts
 // TODO: move panel to global settings panel (move load & save to main pulldown, or to toolbox?)
-// INFO: how about a small tool box for quick preset selection and diabeling of individual snaps?
+// INFO: how about a small tool box for quick preset selection and disabeling of individual snaps?
 
 void select_layout_suite_cb(Fl_Widget *, void *user_data);
 
@@ -416,7 +416,7 @@ void Fd_Layout_Suite::name(const char *n) {
 }
 
 /**
- Initialise the class for first use.
+ Initialize the class for first use.
  */
 void Fd_Layout_Suite::init() {
   name_ = NULL;
@@ -839,7 +839,7 @@ void Fd_Layout_List::capacity(int n) {
 
 /**
  \brief Clone the currently selected suite and append it to the list.
- Selectes the new layout and updates the UI.
+ Selects the new layout and updates the UI.
  */
 int Fd_Layout_List::add(const char *name) {
   if (list_size_ == list_capacity_) {
@@ -964,7 +964,7 @@ static Fl_Group *parent(Fd_Snap_Data &d) {
  \param[in] x_ref position of moving point
  \param[in] x_snap position of target point
  \return 1 if the points are not within range and won;t be considered
- \return 0 if the point is as close as another in a prevoius action
+ \return 0 if the point is as close as another in a previous action
  \return -1 if this point is closer than any previous check, and this is the
     new distance to beat.
  */
@@ -1042,7 +1042,7 @@ void Fd_Snap_Action::check_all(Fd_Snap_Data &data) {
 }
 
 /**
- \brief Draw a visual indicator for all sanp actions that were applied during the last check.
+ \brief Draw a visual indicator for all snap actions that were applied during the last check.
  Only one snap coordinate can win. FLUID chooses the one that is closest to
  the current user event. If two or more snap actions suggest the same
  coordinate, all of them will be drawn.
@@ -1634,9 +1634,9 @@ Fd_Snap_Widget_Ideal_Height snap_widget_ideal_height;
 // ---- snap actions list ---------------------------------------------- MARK: -
 
 /**
- /brief The list of all snap actions availabel to FLUID.
+ /brief The list of all snap actions available to FLUID.
  New snap actions can be appended to the list. If multiple snap actions
- with different corrdinates, but the same sanp distance are found, the last
+ with different coordinates, but the same snap distance are found, the last
  action in the list wins. All snap actions with the same distance and same
  winning coordinates are drawn in the overlay plane.
  */
diff --git a/fluid/Fd_Snap_Action.h b/fluid/Fd_Snap_Action.h
index 336a591d6..e0c99b273 100644
--- a/fluid/Fd_Snap_Action.h
+++ b/fluid/Fd_Snap_Action.h
@@ -94,7 +94,7 @@ class Fd_Layout_Suite {
 public:
   char *name_;                  ///< name of the suite
   char *menu_label;             ///< label text used in pulldown menu
-  Fd_Layout_Preset *layout[3];  ///< presetes for application, dialog, and toolbox windows
+  Fd_Layout_Preset *layout[3];  ///< presets for application, dialog, and toolbox windows
   int storage_;                 ///< storage location (see FD_STORE_INTERNAL, etc.)
   void write(Fl_Preferences &prefs);
   void read(Fl_Preferences &prefs);
@@ -113,7 +113,7 @@ public:
  \brief Manage all layout suites that are available to the user.
 
  FLUID has two built-in suites. More suites can be cloned or added and stored
- as a user preference, as part of an .fl project file, or in a seperate file
+ as a user preference, as part of an .fl project file, or in a separate file
  for import/export and sharing.
  */
 class Fd_Layout_List {
diff --git a/fluid/Fl_Function_Type.cxx b/fluid/Fl_Function_Type.cxx
index e9e53f175..91bb3b2c9 100644
--- a/fluid/Fl_Function_Type.cxx
+++ b/fluid/Fl_Function_Type.cxx
@@ -1,7 +1,7 @@
 //
 // C function type code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2021 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -62,7 +62,7 @@ static char buffer[128]; // for error messages
 
 /**
  Check a quoted string contains a character.
- This is used to find a matchin " or ' in a string.
+ This is used to find a matching " or ' in a string.
  \param[inout] c start searching here, return where we found \c type
  \param[in] type find this character
  \return NULL if the character was found, else a pointer to a static string
@@ -112,7 +112,7 @@ const char *_c_check(const char * & c, int type) {
       break;
 //    case '#':
 //      // treat cpp directives as a comment:
-//      // Matt: a '#' character can appear as a concatenator when defining macros
+//      // Matt: a '#' character can appear as a concatenation when defining macros
 //      // Matt: so instead we just silently ignore the '#'
 //      while (*c != '\n' && *c) c++;
 //      break;
@@ -163,7 +163,7 @@ const char *c_check(const char *c, int type) {
   return _c_check(c,type);
 }
 
-// ---- Fl_Function_Type implemntation
+// ---- Fl_Function_Type implementation
 
 /** \class Fl_Function_Type
  Manage a C++ function node in the Fluid design.
@@ -609,7 +609,7 @@ void Fl_Code_Type::open() {
     const char *cmd = G_external_editor_command;
     const char *code = name();
     if ( editor_.open_editor(cmd, code) == 0 )
-      return;   // return if editor opened ok, fallthru to built-in if not
+      return;   // return if editor opened ok, fall thru to built-in if not
   }
   // Use built-in code editor..
   if (!code_panel) make_code_panel();
@@ -710,7 +710,7 @@ int Fl_Code_Type::handle_editor_changes() {
   return 0;
 }
 
-// ---- Fl_CodeBlock_Type implemntation
+// ---- Fl_CodeBlock_Type implementation
 
 /** \class Fl_CodeBlock_Type
  Manage two blocks of C++ code enclosing its children.
@@ -1578,7 +1578,7 @@ void Fl_Comment_Type::read_property(Fd_Project_Reader &f, const char *c) {
 /**
  Load available preset comments.
  Fluid comes with GPL and LGPL preset for comments. Users can
- add their own presets which are stored per user in a seperate
+ add their own presets which are stored per user in a separate
  preferences database.
  */
 static void load_comments_preset(Fl_Preferences &menu) {
diff --git a/fluid/Fl_Menu_Type.cxx b/fluid/Fl_Menu_Type.cxx
index 75679e835..4b219671b 100644
--- a/fluid/Fl_Menu_Type.cxx
+++ b/fluid/Fl_Menu_Type.cxx
@@ -7,7 +7,7 @@
 // This file also contains code to make Fl_Menu_Button, Fl_Menu_Bar,
 // etc widgets.
 //
-// Copyright 1998-2010 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -105,7 +105,7 @@ void Fl_Input_Choice_Type::build_menu() {
     }
     // Menus are already built during the .fl file reading process, so if the
     // end of a menu list is not read yet, the end markers (label==NULL) will
-    // not be set, and deleting dependants will randomly free memory.
+    // not be set, and deleting dependents will randomly free memory.
     // Clearing the array should avoid that.
     memset( (void*)w->menu(), 0, menusize * sizeof(Fl_Menu_Item) );
     // fill them all in:
@@ -556,7 +556,7 @@ void Fl_Menu_Base_Type::build_menu() {
     }
     // Menus are already built during the .fl file reading process, so if the
     // end of a menu list is not read yet, the end markers (label==NULL) will
-    // not be set, and deleting dependants will randomly free memory.
+    // not be set, and deleting dependents will randomly free memory.
     // Clearing the array should avoid that.
     memset( (void*)w->menu(), 0, menusize * sizeof(Fl_Menu_Item) );
     // fill them all in:
diff --git a/fluid/Fl_Type.cxx b/fluid/Fl_Type.cxx
index 9ed867151..d98db5883 100644
--- a/fluid/Fl_Type.cxx
+++ b/fluid/Fl_Type.cxx
@@ -1,7 +1,7 @@
 //
 // Widget type code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2021 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -300,7 +300,7 @@ void fixvisible(Fl_Type *p) {
   }
 }
 
-// ---- implemenation of Fl_Type
+// ---- implementation of Fl_Type
 
 /** \var Fl_Type *Fl_Type::parent
  Link to the parent node in the tree structure.
@@ -349,7 +349,7 @@ Fl_Type::Fl_Type() {
 
  The destructor removes itself from the doubly linked list. This is dangerous,
  because the node does not know if it is part of the widget tree, or if it is
- in a seperate tree. We try to take care of that as well as possible.
+ in a separate tree. We try to take care of that as well as possible.
  */
 Fl_Type::~Fl_Type() {
   // warning: destructor only works for widgets that have been add()ed.
diff --git a/fluid/Fl_Widget_Type.cxx b/fluid/Fl_Widget_Type.cxx
index 8556de03b..28c24939d 100644
--- a/fluid/Fl_Widget_Type.cxx
+++ b/fluid/Fl_Widget_Type.cxx
@@ -356,7 +356,7 @@ void name_public_cb(Fl_Choice* i, void* v) {
 
 /* Treating UNDO for text widget.
 
- Goal: we want to continiously update the UI while the user is typing text
+ Goal: we want to continuously update the UI while the user is typing text
  (changing the label, in this case). Source View does deferred updates, and
  the widget browser and widget panel update on every keystroke. At the same
  time, we want to limit undo actions to few and logical units.
@@ -895,7 +895,7 @@ void wc_relative_cb(Fl_Choice *i, void *v) {
 ////////////////////////////////////////////////////////////////
 
 // turn number to string or string to number for saving to file:
-// does not work for hierarchial menus!
+// does not work for hierarchical menus!
 
 const char *item_name(Fl_Menu_Item* m, int i) {
   if (m) {
diff --git a/fluid/align_widget.cxx b/fluid/align_widget.cxx
index ecfea0dc4..acf7670bf 100644
--- a/fluid/align_widget.cxx
+++ b/fluid/align_widget.cxx
@@ -1,7 +1,7 @@
 //
 // Alignment code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2010 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -24,8 +24,8 @@
 #include <FL/Fl_Window.H>
 
 /**
- the first behaviour always uses the first selected widget as a reference
- the second behaviour uses the largest widget (most extreme positions) as
+ the first behavior always uses the first selected widget as a reference
+ the second behavior uses the largest widget (most extreme positions) as
  a reference.
  */
 #define BREAK_ON_FIRST break
@@ -236,7 +236,7 @@ void align_widget_cb(Fl_Widget*, long how)
           if (w->window()) w->window()->redraw();
         }
     break;
-  //---- space evently
+  //---- space evenly
   case 20: // space evenly across
     left = max; right = min; wdt = 0, n = 0;
     for (o = Fl_Type::first; o; o = o->next)
diff --git a/fluid/code.cxx b/fluid/code.cxx
index 452aa8b67..7a3725ee0 100644
--- a/fluid/code.cxx
+++ b/fluid/code.cxx
@@ -1,7 +1,7 @@
 //
 // Code output routines for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2021 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -44,7 +44,7 @@ int is_id(char c) {
 }
 
 /**
- Write a file that contains all label and tooltip strings for internationalisation.
+ Write a file that contains all label and tooltip strings for internationalization.
  */
 int write_strings(const char *sfile) {
   FILE *fp = fl_fopen(sfile, "w");
@@ -187,7 +187,7 @@ Fd_Identifier_Tree::~Fd_Identifier_Tree() {
 
 /** \brief Return a unique name for the given object.
 
- This function combines the anem and label into an identifier. It then checks
+ This function combines the name and label into an identifier. It then checks
  if that id was already taken by another object, and if so, appends a
  hexadecimal value which is incremented until the id is unique in this file.
 
@@ -385,7 +385,7 @@ bool Fd_Code_Writer::c_contains(void *pp) {
  Adds " before and after the text.
 
  A list of control characters and ", ', and \\ are escaped by adding a \\ in
- front of them. Escape ?? by wrinting ?\\?. All other characters that are not
+ front of them. Escape ?? by writing ?\\?. All other characters that are not
  between 32 and 126 inclusive will be escaped as octal characters.
 
  This function is utf8 agnostic.
@@ -610,7 +610,7 @@ void Fd_Code_Writer::write_hc(const char *indent, int n, const char* c, const ch
 
 /**
  Write one or more lines of code, indenting each one of them.
- \param[in] textlines one or more lines of text, seperated by \\n
+ \param[in] textlines one or more lines of text, separated by \\n
  */
 void Fd_Code_Writer::write_c_indented(const char *textlines, int inIndent, char inTrailwWith) {
   if (textlines) {
@@ -738,7 +738,7 @@ int Fd_Code_Writer::write_code(const char *s, const char *t, bool to_sourceview)
       first_type->code_position = (int)ftell(code_file);
       first_type->header_position = (int)ftell(header_file);
     }
-    // it is ok to write non-recusive code here, because comments have no children or code2 blocks
+    // it is ok to write non-recursive code here, because comments have no children or code2 blocks
     first_type->write_code1(*this);
     if (write_sourceview) {
       first_type->code_position_end = (int)ftell(code_file);
diff --git a/fluid/custom_widgets.cxx b/fluid/custom_widgets.cxx
index df4405196..170ef44a2 100644
--- a/fluid/custom_widgets.cxx
+++ b/fluid/custom_widgets.cxx
@@ -151,18 +151,18 @@ void Fluid_Coord_Input::callback_handler_cb(Fluid_Coord_Input *This, void *v) {
 void Fluid_Coord_Input::callback_handler(void *v) {
   if (user_callback_)
     (*user_callback_)(this, v);
-  // do *not* update the value to show the evaluated fomule here, because the
+  // do *not* update the value to show the evaluated formula here, because the
   // values of the variables have already updated after the user callback.
 }
 
 /**
  Get the value of a variable.
- Collects all conesecutive ASCII letters into a variable name, scans the
+ Collects all consecutive ASCII letters into a variable name, scans the
  Variable list for that name, and then calls the corresponding callback from
  the Variable array.
  \param s points to the first character of the variable name, must point after
     the last character of the variable name when returning.
- \return the integer value that wasf= found or calculated
+ \return the integer value that was found or calculated
  */
 int Fluid_Coord_Input::eval_var(uchar *&s) const {
   if (!vars_)
diff --git a/fluid/factory.cxx b/fluid/factory.cxx
index 2eb0bbca3..8e6164aa1 100644
--- a/fluid/factory.cxx
+++ b/fluid/factory.cxx
@@ -658,7 +658,7 @@ static Fl_Menu_Item input_type_menu[] = {
 
 /**
  \brief Manage simple text input widgets.
- The managed class is derived from Fl_Input_, but for simpleicity, deriving from
+ The managed class is derived from Fl_Input_, but for simplicity, deriving from
  Fl_Widget_Type seems sufficient here.
  */
 class Fl_Input_Type : public Fl_Widget_Type
@@ -773,7 +773,7 @@ static Fl_Output_Type Fl_Output_type;
 
 /**
  \brief Manage the Text Display as a base class.
- Fl_Text_Dissplay is actually derived from Fl_Group, but for FLUID, deriving
+ Fl_Text_Display is actually derived from Fl_Group, but for FLUID, deriving
  the type from Widget is better.
  */
 class Fl_Text_Display_Type : public Fl_Widget_Type
@@ -1125,7 +1125,7 @@ static Fl_Type *known_types[] = {
 /**
  Create and add a new widget to the widget tree.
 
- Fluid will try to set a default postion for widgets to the user's expectation.
+ Fluid will try to set a default position for widgets to the user's expectation.
  Using the context menu will put new widgets at the position of the mouse click.
  Pulldown menu and bin actions will generate widgets no too far from previously
  added widgets in the same group.
diff --git a/fluid/file.cxx b/fluid/file.cxx
index 3e7e7348d..1c49d8574 100644
--- a/fluid/file.cxx
+++ b/fluid/file.cxx
@@ -210,7 +210,7 @@ int Fd_Project_Reader::read_quoted() {      // read whatever character is after
  \param[in] paste if set, merge into existing design, else replace design
  \param[in] strategy add nodes after current or as last child
  \param[in] skip_options this is set if the options were already found in
- a previous call, and there is no need to waste time searchingg for them.
+ a previous call, and there is no need to waste time searching for them.
  */
 void Fd_Project_Reader::read_children(Fl_Type *p, int paste, Strategy strategy, char skip_options) {
   Fl_Type::current = p;
diff --git a/fluid/fluid.cxx b/fluid/fluid.cxx
index 2d5b05bde..9871b3f9c 100644
--- a/fluid/fluid.cxx
+++ b/fluid/fluid.cxx
@@ -1424,9 +1424,9 @@ extern void layout_suite_marker(Fl_Widget *, void *user_data);
  \c New_Menu creates new widgets and is explained in detail in another location.
 
  \see New_Menu
- \todo This menu need some major modernisation. Menus are too long and their
+ \todo This menu need some major modernization. Menus are too long and their
     sorting is not always obvious.
- \todo Shortcuts are all over the palce (Alt, Ctrl, Command, Shift-Ctrl,
+ \todo Shortcuts are all over the place (Alt, Ctrl, Command, Shift-Ctrl,
     function keys), and there should be a help page listing all shortcuts.
  */
 Fl_Menu_Item Main_Menu[] = {
@@ -2072,7 +2072,7 @@ static void sigint(SIGARG) {
  user interfaces and write the C++ files to manage them,
 
  Fluid can run form the command line in batch mode to convert .fl design files
- into C++ source and header files. In batch mode, no diplay is needed,
+ into C++ source and header files. In batch mode, no display is needed,
  particularly no X11 connection will be attempted on Linux/Unix.
 
  \param[in] argc number of arguments in the list
@@ -2086,7 +2086,7 @@ static void sigint(SIGARG) {
 int main(int argc,char **argv) {
   int i = 1;
 
-  setlocale(LC_ALL, "");      // enable multilanguage errors in file chooser
+  setlocale(LC_ALL, "");      // enable multi-language errors in file chooser
   setlocale(LC_NUMERIC, "C"); // make sure numeric values are written correctly
 
   if (   (Fl::args(argc,argv,i,arg) == 0)   // unsupported argument found