diff --git a/CHANGES b/CHANGES
index a5d897e..6018ea0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -204,7 +204,7 @@
   Added simple sRGB support (Glenn R-P)
   Easier conditional compiling, e.g.,
     define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
-    all configurable options can be selected from command-line instead
+    all configurable options can be selected from command line instead
     of having to edit pngconf.h (Glenn R-P)
   Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
   Added more conditions for png_do_background, to avoid changing
@@ -942,7 +942,7 @@
 Version 1.0.9beta1 [November 10, 2000]
   Fixed typo in scripts/makefile.hpux
   Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
-  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+  Fixed sequence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
   Changed "cdrom.com" in documentation to "libpng.org"
   Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
   Changed type of "params" from voidp to png_voidp in png_read|write_png().
@@ -2295,7 +2295,7 @@
   Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
 
 Version 1.4.0beta59 [May 15, 2009]
-  Reformated sources in libpng style (3-space indentation, comment format)
+  Reformatted sources in libpng style (3-space indentation, comment format)
   Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
   Added sections about the git repository and our coding style to the
     documentation
@@ -2661,7 +2661,7 @@
 
 Version 1.4.1beta07 [February 6, 2010]
   Folded some long lines in the source files.
-  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+  Added definable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
     and a PNG_USER_LIMITS_SUPPORTED flag.
   Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
     png_ptr->png_user_chunk_malloc_max.
@@ -3919,7 +3919,7 @@
     version checking to configure.ac
   Improved pngstest speed by not doing redundant tests and add const to
     the background parameter of png_image_finish_read. The --background
-    option is now done automagically only when required, so that commandline
+    option is now done automagically only when required, so that command-line
     option no longer exists.
   Cleaned up pngpriv.h to consistently declare all functions and data.
     Also eliminated PNG_CONST_DATA, which is apparently not needed but we
diff --git a/autogen.sh b/autogen.sh
index a46daf6..9c8830a 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -77,7 +77,7 @@
    config.sub configure depcomp install-sh ltmain.sh missing\
    test-driver"
 #
-# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# Files generated by versions of autoconf >2.68 or automake >1.13 (i.e. later
 # versions than those required by configure.ac):
 libpng_autotools_extra="compile config.h.in~"
 #
diff --git a/contrib/libtests/makepng.c b/contrib/libtests/makepng.c
index e911c06..a866fc1 100644
--- a/contrib/libtests/makepng.c
+++ b/contrib/libtests/makepng.c
@@ -496,7 +496,7 @@
          case 32:
          case 48:
          case 64:
-            /* The rows are filled by an alogorithm similar to the above, in the
+            /* The rows are filled by an algorithm similar to the above, in the
              * first row pixel bytes are all equal, increasing from 0 by 1 for
              * each pixel.  In the second row the bytes within a pixel are
              * incremented 1,3,5,7,... from the previous row byte.  Using an odd
diff --git a/contrib/libtests/pngstest.c b/contrib/libtests/pngstest.c
index cd4f3cd..973e60f 100644
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@@ -1151,7 +1151,7 @@
  *
  * 2) Remove color by mapping to grayscale.  (Grayscale to color is a no-op.)
  *
- * 3) Convert between 8-bit and 16-bit components.  (Both directtions are
+ * 3) Convert between 8-bit and 16-bit components.  (Both directions are
  *    relevant.)
  *
  * This gives the following base format conversion matrix:
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 49eed5c..6a7422e 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -6719,7 +6719,7 @@
    unsigned int out, png_byte sample_depth, double err, double limit,
    const char *name, double digitization_error)
 {
-   /* Compare the scaled, digitzed, values of our local calculation (in+-err)
+   /* Compare the scaled, digitized, values of our local calculation (in+-err)
     * with the digitized values libpng produced;  'sample_depth' is the actual
     * digitization depth of the libpng output colors (the bit depth except for
     * palette images where it is always 8.)  The check on 'err' is to detect
@@ -9065,7 +9065,7 @@
 static int
 image_transform_test_counter(png_uint_32 counter, unsigned int max)
 {
-   /* Test the list to see if there is any point contining, given a current
+   /* Test the list to see if there is any point continuing, given a current
     * counter and a 'max' value.
     */
    image_transform *next = image_transform_first;
diff --git a/contrib/libtests/tarith.c b/contrib/libtests/tarith.c
index ead77e9..e35b7ab 100644
--- a/contrib/libtests/tarith.c
+++ b/contrib/libtests/tarith.c
@@ -952,7 +952,7 @@
 
 /**************************** VALIDATION TESTS ********************************/
 /* Various validation routines are included herein, they require some
- * definition for png_warning and png_error, seetings of VALIDATION:
+ * definition for png_warning and png_error, settings of VALIDATION:
  *
  * 1: validates the ASCII to floating point conversions
  * 2: validates png_muldiv
diff --git a/contrib/pngminus/LICENSE.txt b/contrib/pngminus/LICENSE.txt
index 00878a9..a8d4137 100644
--- a/contrib/pngminus/LICENSE.txt
+++ b/contrib/pngminus/LICENSE.txt
@@ -16,7 +16,7 @@
 The software is provided "as is", without warranty of any kind, express or
 implied, including but not limited to the warranties of merchantability,
 fitness for a particular purpose and noninfringement. In no event shall the
-authors or copyight holders be liable for any claim, damages or other
+authors or copyright holders be liable for any claim, damages or other
 liability, whether in an action of contract, tort or otherwise, arising from,
 out of or in connection with the software or the use or other dealings in the
 software.
diff --git a/contrib/tools/pngfix.c b/contrib/tools/pngfix.c
index 54a467d..cdf3f1c 100644
--- a/contrib/tools/pngfix.c
+++ b/contrib/tools/pngfix.c
@@ -867,7 +867,7 @@
     * signature (in length,type).
     *
     * When a chunk control structure is instantiated these values are copied
-    * into the structure and can then be overritten with the data for the next
+    * into the structure and can then be overwritten with the data for the next
     * chunk.
     */
    fpos_t         data_pos;      /* Position of first byte of chunk data */
diff --git a/contrib/visupng/VisualPng.c b/contrib/visupng/VisualPng.c
index 6baa3b6..6f7b1df 100644
--- a/contrib/visupng/VisualPng.c
+++ b/contrib/visupng/VisualPng.c
@@ -103,7 +103,7 @@
         return 0;
     }
 
-    /* if filename given on commandline, store it */
+    /* if filename given on command line, store it */
     if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
         if (szCmdLine[0] == '"')
             strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
diff --git a/pngpriv.h b/pngpriv.h
index b8a73b6..75411d9 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -1910,7 +1910,7 @@
  */
 #define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
 
-/* Result codes for the parser (boolean - true meants ok, false means
+/* Result codes for the parser (boolean - true means ok, false means
  * not ok yet.)
  */
 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */