diff --git a/README b/README
index 925fd8c..e2d418e 100644
--- a/README
+++ b/README
@@ -4,12 +4,12 @@
 See INSTALL for instructions on how to install libpng.
 
 Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
-libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
-or lpng*.7z or lpng*.zip if you want DOS-style line endings.
+libpng-*.tar.xz or if you want UNIX-style line endings in the text
+files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
-fact that it's the first release fool you.  The libpng library has been in
-extensive use and testing since mid-1995.  By late 1997 it had
+fact that it's the first release fool you.  The libpng library has been
+in extensive use and testing since mid-1995.  By late 1997 it had
 finally gotten to the stage where there hadn't been significant
 changes to the API in some time, and people have a bad feeling about
 libraries with versions < 1.0.  Version 1.0.0 was released in
@@ -60,84 +60,48 @@
 to set different actions based on whether the CRC error occurred in a
 critical or an ancillary chunk.
 
-The changes made to the library, and bugs fixed are based on discussions
-on the PNG-implement mailing list and not on material submitted
-privately to Guy, Andreas, or Glenn.  They will forward any good
-suggestions to the list.
-
-For a detailed description on using libpng, read libpng-manual.txt.  For
-examples of libpng in a program, see example.c and pngtest.c.  For usage
-information and restrictions (what little they are) on libpng, see
-png.h.  For a description on using zlib (the compression library used by
-libpng) and zlib's restrictions, see zlib.h
+For a detailed description on using libpng, read libpng-manual.txt.
+For examples of libpng in a program, see example.c and pngtest.c.  For
+usage information and restrictions (what little they are) on libpng,
+see png.h.  For a description on using zlib (the compression library
+used by libpng) and zlib's restrictions, see zlib.h
 
 I have included a general makefile, as well as several machine and
-compiler specific ones, but you may have to modify one for your own needs.
+compiler specific ones, but you may have to modify one for your own
+needs.
 
 You should use zlib 1.0.4 or later to run this, but it MAY work with
 versions as old as zlib 0.95.  Even so, there are bugs in older zlib
 versions which can cause the output of invalid compression streams for
-some images.  You will definitely need zlib 1.0.4 or later if you are
-taking advantage of the MS-DOS "far" structure allocation for the small
-and medium memory models.  You should also note that zlib is a
-compression library that is useful for more things than just PNG files.
-You can use zlib as a drop-in replacement for fread() and fwrite() if
-you are so inclined.
+some images.
 
-zlib should be available at the same place that libpng is, or at zlib.net.
+You should also note that zlib is a compression library that is useful
+for more things than just PNG files.  You can use zlib as a drop-in
+replacement for fread() and fwrite(), if you are so inclined.
+
+zlib should be available at the same place that libpng is, or at
+https://zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
 these at http://www.libpng.org/pub/png/pngdocs.html .
 
 This code is currently being archived at libpng.sourceforge.io in the
-[DOWNLOAD] area, and at http://libpng.download/src .  If you
-can't find it in any of those places, e-mail me, and I'll help you find it.
-
-I am not a lawyer, but I believe that the Export Control Classification
-Number (ECCN) for libpng is EAR99, which means not subject to export
-controls or International Traffic in Arms Regulations (ITAR) because it
-is open source, publicly available software, that does not contain any
-encryption software.  See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
-
-If you have any code changes, requests, problems, etc., please e-mail
-them to me.  Also, I'd appreciate any make files or project files,
-and any modifications you needed to make to get libpng to compile,
-along with a #define variable to tell what compiler/system you are on.
-If you needed to add transformations to libpng, or wish libpng would
-provide the image in a different way, drop me a note (and code, if
-possible), so I can consider supporting the transformation.
-Finally, if you get any warning messages when compiling libpng
-(note: not zlib), and they are easy to fix, I'd appreciate the
-fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
+[DOWNLOAD] area, and at http://libpng.download/src .
 
 This release was created and will be supported by myself (of course
-based in a large way on Guy's and Andreas' earlier work), and the PNG
-development group.
+based in a large way on Glenn's, Guy's and Andreas' earlier work), and
+the PNG development group.
 
 Send comments/corrections/commendations to png-mng-implement at
 lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
 to subscribe).
 
-You can't reach Guy, the original libpng author, at the addresses
-given in previous versions of this document.  He and Andreas will
-read mail addressed to the png-implement list, however.
-
-Please do not send general questions about PNG.  Send them to
-png-mng-misc at lists.sf.net (subscription required; visit
+Send general questions about the PNG specification to png-mng-misc
+at lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
-subscribe).  If you have a question about something
-in the PNG specification that is related to using libpng, send it
-to me.  Send me any questions that start with "I was using libpng,
-and ...".  If in doubt, send questions to me.  I'll bounce them
-to others, if necessary.
-
-Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for twenty years now, and it is official and
-finished.  If you have suggestions for libpng, however, I'll
-gladly listen.  Even if your suggestion is not used immediately,
-it may be used later.
+subscribe).
 
 Files in this distribution:
 
diff --git a/TODO b/TODO
index 36d6092..562dab0 100644
--- a/TODO
+++ b/TODO
@@ -1,30 +1,23 @@
-/*
 TODO - list of things to do for libpng:
 
-Final bug fixes.
-Better C++ wrapper/full C++ implementation?
-Fix problem with C++ and EXTERN "C".
-cHRM transformation.
-Remove setjmp/longjmp usage in favor of returning error codes. As a start on
-  this, minimize the use of png_error(), replacing them with
-  png_warning(); return(0); or similar.
-Palette creation.
-Add "grayscale->palette" transformation and "palette->grayscale" detection.
-Improved dithering.
-Multi-lingual error and warning message support.
-Complete sRGB transformation (presently it simply uses gamma=0.45455).
-Man pages for function calls.
-Better documentation.
-Better filter selection
-   (counting huffman bits/precompression?  filter inertia?  filter costs?).
-Histogram creation.
-Text conversion between different code pages (Latin-1 -> Mac and DOS).
-Avoid building gamma tables whenever possible.
-Use greater precision when changing to linear gamma for compositing against
-  background and doing rgb-to-gray transformation.
-Investigate pre-incremented loop counters and other loop constructions.
-Add interpolated method of handling interlacing.
-Extend pngvalid.c to validate more of the libpng transformations.
-Refactor preprocessor conditionals to compile entire statements
-
-*/
+* Fix all defects (duh!)
+* Better C++ wrapper / full C++ implementation (?)
+* Fix the problems with C++ and 'extern "C"'.
+* cHRM transformation.
+* Palette creation.
+* "grayscale->palette" transformation and "palette->grayscale" detection.
+* Improved dithering.
+* Multi-lingual error and warning message support.
+* Complete sRGB transformation.  (Currently it simply uses gamma=0.45455.)
+* Man pages for function calls.
+* Better documentation.
+* Better filter selection
+  (e.g., counting huffman bits/precompression; filter inertia; filter costs).
+* Histogram creation.
+* Text conversion between different code pages (e.g., Latin-1 -> Mac).
+* Avoid building gamma tables whenever possible.
+* Greater precision in changing to linear gamma for compositing against
+  background, and in doing rgb-to-gray transformations.
+* Investigate pre-incremented loop counters and other loop constructions.
+* Interpolated method of handling interlacing.
+* More validations for libpng transformations.
diff --git a/libpng-manual.txt b/libpng-manual.txt
index b14a534..8d66f25 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,7 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.35 - July 15, 2018
- Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 2018 Cosmin Truta
  Copyright (c) 1998-2018 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
@@ -12,7 +11,7 @@
 
  libpng versions 0.97, January 1998, through 1.6.35 - July 15, 2018
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2017 Glenn Randers-Pehrson
+ Copyright (c) 1998-2018 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -44,7 +43,6 @@
  XIII. Detecting libpng
   XIV. Source code repository
    XV. Coding style
-  XVI. Y2K Compliance in libpng
 
 I. Introduction
 
@@ -4520,7 +4518,7 @@
 having level = 0 will be printed.  There aren't any such statements in
 this version of libpng, but if you insert some they will be printed.
 
-VII.  MNG support
+VII. MNG support
 
 The MNG specification (available at http://www.libpng.org/pub/mng) allows
 certain extensions to PNG for PNG images that are embedded in MNG datastreams.
@@ -4547,7 +4545,7 @@
 them.  You may wish to consider using libmng (available at
 https://www.libmng.com/) instead.
 
-VIII.  Changes to Libpng from version 0.88
+VIII. Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -4602,7 +4600,7 @@
 
    png_uint_32 application_vn = PNG_LIBPNG_VER;
 
-IX.  Changes to Libpng from version 1.0.x to 1.2.x
+IX. Changes to Libpng from version 1.0.x to 1.2.x
 
 Support for user memory management was enabled by default.  To
 accomplish this, the functions png_create_read_struct_2(),
@@ -4699,7 +4697,7 @@
     png_set_expand_gray_1_2_4_to_8()
 which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
 
-X.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
 
 Private libpng prototypes and macro definitions were moved from
 png.h and pngconf.h into a new pngpriv.h header file.
@@ -4809,7 +4807,7 @@
 
 We removed the trailing '.' from the warning and error messages.
 
-XI.  Changes to Libpng from version 1.4.x to 1.5.x
+XI. Changes to Libpng from version 1.4.x to 1.5.x
 
 From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
 function) incorrectly returned a value of type png_uint_32.
@@ -5067,7 +5065,7 @@
 to choose at app buildtime whether or not to use macros (previously
 impossible because the functions weren't in the default build.)
 
-XII.  Changes to Libpng from version 1.5.x to 1.6.x
+XII. Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
 example in contrib/examples/pngtopng.c).  The new publicly visible API
@@ -5230,7 +5228,7 @@
 containing the profile to the calling application which must do its own
 decoding.
 
-XIII.  Detecting libpng
+XIII. Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
 changed, and is unaffected by conditional compilation macros.  It is the
@@ -5255,7 +5253,7 @@
     https://sourceforge.net/p/libpng/code/ci/libpng16/tree/
 
 Patches can be sent to png-mng-implement at lists.sourceforge.net or
-you can upload them to the libpng bug tracker at
+uploaded to the libpng bug tracker at
 
     https://libpng.sourceforge.io/
 
@@ -5405,58 +5403,3 @@
 Lines do not exceed 80 characters.
 
 Other rules can be inferred by inspecting the libpng source.
-
-XVI. Y2K Compliance in libpng
-
-Since the PNG Development group is an ad-hoc body, we can't make
-an official declaration.
-
-This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.35 are Y2K compliant.  It is my belief that earlier
-versions were also Y2K compliant.
-
-Libpng only has two year fields.  One is a 2-byte unsigned integer
-that will hold years up to 65535.  The other, which is deprecated,
-holds the date in text format, and will hold years up to 9999.
-
-The integer is
-    "png_uint_16 year" in png_time_struct.
-
-The string is
-    "char time_buffer[29]" in png_struct.  This is no longer used
-in libpng-1.6.x and will be removed from libpng-1.7.0.
-
-There are seven time-related functions:
-
-    png_convert_to_rfc_1123_buffer() in png.c
-      (formerly png_convert_to_rfc_1152() in error, and
-      also formerly png_convert_to_rfc_1123())
-    png_convert_from_struct_tm() in pngwrite.c, called
-      in pngwrite.c
-    png_convert_from_time_t() in pngwrite.c
-    png_get_tIME() in pngget.c
-    png_handle_tIME() in pngrutil.c, called in pngread.c
-    png_set_tIME() in pngset.c
-    png_write_tIME() in pngwutil.c, called in pngwrite.c
-
-All appear to handle dates properly in a Y2K environment.  The
-png_convert_from_time_t() function calls gmtime() to convert from system
-clock time, which returns (year - 1900), which we properly convert to
-the full 4-digit year.  There is a possibility that applications using
-libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
-function, or that they are incorrectly passing only a 2-digit year
-instead of "year - 1900" into the png_convert_from_struct_tm() function,
-but this is not under our control.  The libpng documentation has always
-stated that it works with 4-digit years, and the APIs have been
-documented as such.
-
-The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
-integer to hold the year, and can hold years as large as 65535.
-
-zlib, upon which libpng depends, is also Y2K compliant.  It contains
-no date-related code.
-
-
-   Glenn Randers-Pehrson
-   libpng maintainer
-   PNG Development Group
diff --git a/libpng.3 b/libpng.3
index 01cd905..c39580c 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,11 +1,11 @@
-.TH LIBPNG 3 "July 15, 2018"
+.TH LIBPNG 3 "2018-Jul-29"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.35
-.SH SYNOPSIS
-\fB
-#include <png.h>\fP
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.36.git
 
-\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP
+.SH SYNOPSIS
+\fB#include <png.h>\fP
+
+\fBpng_uint_32 png_access_version_number (void);\fP
 
 \fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
 
@@ -35,7 +35,7 @@
 
 \fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
 
-\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask)\fP\fB);\fP
+\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask\fP\fB);\fP
 
 \fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
 
@@ -233,9 +233,9 @@
 
 \fBint png_image_write_to_file (png_imagep \fP\fIimage\fP\fB, const char \fP\fI*file\fP\fB, int \fP\fIconvert_to_8bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP
 
-\fBint png_image_write_to_memory (png_imagep \fP\fIimage\fP\fB, void \fP\fI*memory\fP\fB, png_alloc_size_t * PNG_RESTRICT \fP\fImemory_bytes\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, const void \fI*colormap)\fP\fB);\fP
+\fBint png_image_write_to_memory (png_imagep \fP\fIimage\fP\fB, void \fP\fI*memory\fP\fB, png_alloc_size_t * PNG_RESTRICT \fP\fImemory_bytes\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, const void \fI*colormap\fP\fB);\fP
 
-\fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap)\fP\fB);\fP
+\fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP
 
 \fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, size_t \fIpng_info_struct_size\fP\fB);\fP
 
@@ -253,9 +253,9 @@
 
 \fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, size_t \fIbuffer_size\fP\fB);\fP
 
-\fBsize_t png_process_data_pause \fP\fI(png_structp\fP\fB, int \fIsave\fP\fB);\fP
+\fBsize_t png_process_data_pause (png_structp \fP\fIpng_ptr\fP\fB, int \fIsave\fP\fB);\fP
 
-\fBpng_uint_32 png_process_data_skip \fI(png_structp\fP\fB);\fP
+\fBpng_uint_32 png_process_data_skip (png_structp \fP\fIpng_ptr\fP\fB);\fP
 
 \fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP
 
@@ -297,7 +297,7 @@
 
 \fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
 
-\fBvoid png_set_check_for_invalid_index(png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
+\fBvoid png_set_check_for_invalid_index (png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
 
 \fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
 
@@ -453,7 +453,7 @@
 
 \fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
 
-\fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP
+\fBvoid png_set_text_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
 
 \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
 
@@ -515,11 +515,11 @@
 .IR zlib(3)
 compression library.
 Following is a copy of the libpng-manual.txt file that accompanies libpng.
+
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.35 - July 15, 2018
- Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 2018 Cosmin Truta
  Copyright (c) 1998-2018 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
@@ -530,7 +530,7 @@
 
  libpng versions 0.97, January 1998, through 1.6.35 - July 15, 2018
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2017 Glenn Randers-Pehrson
+ Copyright (c) 1998-2018 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -562,7 +562,6 @@
  XIII. Detecting libpng
   XIV. Source code repository
    XV. Coding style
-  XVI. Y2K Compliance in libpng
 
 .SH I. Introduction
 
@@ -5038,7 +5037,7 @@
 having level = 0 will be printed.  There aren't any such statements in
 this version of libpng, but if you insert some they will be printed.
 
-.SH VII.  MNG support
+.SH VII. MNG support
 
 The MNG specification (available at http://www.libpng.org/pub/mng) allows
 certain extensions to PNG for PNG images that are embedded in MNG datastreams.
@@ -5065,7 +5064,7 @@
 them.  You may wish to consider using libmng (available at
 https://www.libmng.com/) instead.
 
-.SH VIII.  Changes to Libpng from version 0.88
+.SH VIII. Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -5120,7 +5119,7 @@
 
    png_uint_32 application_vn = PNG_LIBPNG_VER;
 
-.SH IX.  Changes to Libpng from version 1.0.x to 1.2.x
+.SH IX. Changes to Libpng from version 1.0.x to 1.2.x
 
 Support for user memory management was enabled by default.  To
 accomplish this, the functions png_create_read_struct_2(),
@@ -5217,7 +5216,7 @@
     png_set_expand_gray_1_2_4_to_8()
 which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
 
-.SH X.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
 
 Private libpng prototypes and macro definitions were moved from
 png.h and pngconf.h into a new pngpriv.h header file.
@@ -5327,7 +5326,7 @@
 
 We removed the trailing '.' from the warning and error messages.
 
-.SH XI.  Changes to Libpng from version 1.4.x to 1.5.x
+.SH XI. Changes to Libpng from version 1.4.x to 1.5.x
 
 From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
 function) incorrectly returned a value of type png_uint_32.
@@ -5585,7 +5584,7 @@
 to choose at app buildtime whether or not to use macros (previously
 impossible because the functions weren't in the default build.)
 
-.SH XII.  Changes to Libpng from version 1.5.x to 1.6.x
+.SH XII. Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
 example in contrib/examples/pngtopng.c).  The new publicly visible API
@@ -5748,7 +5747,7 @@
 containing the profile to the calling application which must do its own
 decoding.
 
-.SH XIII.  Detecting libpng
+.SH XIII. Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
 changed, and is unaffected by conditional compilation macros.  It is the
@@ -5924,61 +5923,6 @@
 
 Other rules can be inferred by inspecting the libpng source.
 
-.SH XVI. Y2K Compliance in libpng
-
-Since the PNG Development group is an ad-hoc body, we can't make
-an official declaration.
-
-This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.35 are Y2K compliant.  It is my belief that earlier
-versions were also Y2K compliant.
-
-Libpng only has two year fields.  One is a 2-byte unsigned integer
-that will hold years up to 65535.  The other, which is deprecated,
-holds the date in text format, and will hold years up to 9999.
-
-The integer is
-    "png_uint_16 year" in png_time_struct.
-
-The string is
-    "char time_buffer[29]" in png_struct.  This is no longer used
-in libpng-1.6.x and will be removed from libpng-1.7.0.
-
-There are seven time-related functions:
-
-    png_convert_to_rfc_1123_buffer() in png.c
-      (formerly png_convert_to_rfc_1152() in error, and
-      also formerly png_convert_to_rfc_1123())
-    png_convert_from_struct_tm() in pngwrite.c, called
-      in pngwrite.c
-    png_convert_from_time_t() in pngwrite.c
-    png_get_tIME() in pngget.c
-    png_handle_tIME() in pngrutil.c, called in pngread.c
-    png_set_tIME() in pngset.c
-    png_write_tIME() in pngwutil.c, called in pngwrite.c
-
-All appear to handle dates properly in a Y2K environment.  The
-png_convert_from_time_t() function calls gmtime() to convert from system
-clock time, which returns (year - 1900), which we properly convert to
-the full 4-digit year.  There is a possibility that applications using
-libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
-function, or that they are incorrectly passing only a 2-digit year
-instead of "year - 1900" into the png_convert_from_struct_tm() function,
-but this is not under our control.  The libpng documentation has always
-stated that it works with 4-digit years, and the APIs have been
-documented as such.
-
-The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
-integer to hold the year, and can hold years as large as 65535.
-
-zlib, upon which libpng depends, is also Y2K compliant.  It contains
-no date-related code.
-
-
-   Glenn Randers-Pehrson
-   libpng maintainer
-   PNG Development Group
-
 .SH NOTE
 
 Note about libpng version numbers:
@@ -5989,9 +5933,9 @@
 The following table summarizes matters since version 0.89c, which was
 the first widely used release:
 
- source             png.h  png.h  shared-lib
- version            string   int  version
- -------            ------  ----- ----------
+ source               png.h    png.h  shared-lib
+ version              string   int    version
+ -------              ------   -----  ----------
  0.89c "1.0 beta 3"     0.89      89  1.0.89
  0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
  0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
@@ -6026,23 +5970,25 @@
  1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
  1.0.7                    1    10007  (still compatible)
  ...
- 1.0.19                  10    10019  10.so.0.19[.0]
+ 1.0.69                  10    10069  10.so.0.69[.0]
  ...
  1.2.59                  13    10259  12.so.0.59[.0]
  ...
+ 1.4.20                  14    10420  14.so.0.20[.0]
+ ...
  1.5.30                  15    10530  15.so.15.30[.0]
  ...
  1.6.35                  16    10635  16.so.16.35[.0]
 
-Henceforth the source version will match the shared-library minor
-and patch numbers; the shared-library major version number will be
-used for changes in backward compatibility, as it is intended.  The
-PNG_PNGLIB_VER macro, which is not used within libpng but is available
-for applications, is an unsigned integer of the form xyyzz corresponding
-to the source version x.y.z (leading zeros in y and z).  Beta versions
-were given the previous public release number plus a letter, until
-version 1.0.6j; from then on they were given the upcoming public
-release number plus "betaNN" or "rcNN".
+Henceforth the source version will match the shared-library minor and
+patch numbers; the shared-library major version number will be used for
+changes in backward compatibility, as it is intended.
+The PNG_PNGLIB_VER macro, which is not used within libpng but is
+available for applications, is an unsigned integer of the form XYYZZ
+corresponding to the source version X.Y.Z (leading zeros in Y and Z).
+Beta versions were given the previous public release number plus a
+letter, until version 1.0.6j; from then on they were given the upcoming
+public release number plus "betaNN" or "rcNN".
 
 .SH "SEE ALSO"
 .IR libpngpf(3) ", " png(5)
@@ -6079,8 +6025,9 @@
 and this library, the specification takes precedence.
 
 .SH AUTHORS
-This man page: Glenn Randers-Pehrson
-<glennrp at users.sourceforge.net>
+This man page:
+Initially created by Glenn Randers-Pehrson.
+Maintained by Cosmin Truta.
 
 The contributing authors would like to thank all those who helped
 with testing, bug fixes, and patience.  This wouldn't have been
@@ -6088,9 +6035,9 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.35 - July 15, 2018:
+Libpng:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
-Maintained by Glenn Randers-Pehrson.
+Maintained by Cosmin Truta.
 
 Supported by the PNG development group
 .br
@@ -6100,146 +6047,4 @@
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
 to subscribe).
 
-.SH NOTICES:
-
-This copy of the libpng notices is provided for your convenience.  In case of
-any discrepancy between this copy and the notices in the file png.h that is
-included in the libpng distribution, the latter shall prevail.
-
-COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
-
-If you modify libpng you may insert additional notices immediately following
-this sentence.
-
-This code is released under the libpng license.
-
-libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are
-Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
-derived from libpng-1.0.6, and are distributed according to the same
-disclaimer and license as libpng-1.0.6 with the following individuals
-added to the list of Contributing Authors:
-
-   Simon-Pierre Cadieux
-   Eric S. Raymond
-   Mans Rullgard
-   Cosmin Truta
-   Gilles Vollant
-   James Yu
-   Mandar Sahastrabuddhe
-   Google Inc.
-   Vadim Barkov
-
-and with the following additions to the disclaimer:
-
-   There is no warranty against interference with your enjoyment of the
-   library or against infringement.  There is no warranty that our
-   efforts or the library will fulfill any of your particular purposes
-   or needs.  This library is provided with all faults, and the entire
-   risk of satisfactory quality, performance, accuracy, and effort is with
-   the user.
-
-Some files in the "contrib" directory and some configure-generated
-files that are distributed with libpng have other copyright owners and
-are released under other open source licenses.
-
-libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
-libpng-0.96, and are distributed according to the same disclaimer and
-license as libpng-0.96, with the following individuals added to the list
-of Contributing Authors:
-
-   Tom Lane
-   Glenn Randers-Pehrson
-   Willem van Schaik
-
-libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
-and are distributed according to the same disclaimer and license as
-libpng-0.88, with the following individuals added to the list of
-Contributing Authors:
-
-   John Bowler
-   Kevin Bracey
-   Sam Bushell
-   Magnus Holmgren
-   Greg Roelofs
-   Tom Tanner
-
-Some files in the "scripts" directory have other copyright owners
-but are released under this license.
-
-libpng versions 0.5, May 1995, through 0.88, January 1996, are
-Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
-
-For the purposes of this copyright and license, "Contributing Authors"
-is defined as the following set of individuals:
-
-   Andreas Dilger
-   Dave Martindale
-   Guy Eric Schalnat
-   Paul Schmidt
-   Tim Wegner
-
-The PNG Reference Library is supplied "AS IS".  The Contributing Authors
-and Group 42, Inc. disclaim all warranties, expressed or implied,
-including, without limitation, the warranties of merchantability and of
-fitness for any purpose.  The Contributing Authors and Group 42, Inc.
-assume no liability for direct, indirect, incidental, special, exemplary,
-or consequential damages, which may result from the use of the PNG
-Reference Library, even if advised of the possibility of such damage.
-
-Permission is hereby granted to use, copy, modify, and distribute this
-source code, or portions hereof, for any purpose, without fee, subject
-to the following restrictions:
-
-  1. The origin of this source code must not be misrepresented.
-
-  2. Altered versions must be plainly marked as such and must not
-     be misrepresented as being the original source.
-
-  3. This Copyright notice may not be removed or altered from any
-     source or altered source distribution.
-
-The Contributing Authors and Group 42, Inc. specifically permit, without
-fee, and encourage the use of this source code as a component to
-supporting the PNG file format in commercial products.  If you use this
-source code in a product, acknowledgment is not required but would be
-appreciated.
-
-END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
-
-TRADEMARK:
-
-The name "libpng" has not been registered by the Copyright owner
-as a trademark in any jurisdiction.  However, because libpng has
-been distributed and maintained world-wide, continually since 1995,
-the Copyright owner claims "common-law trademark protection" in any
-jurisdiction where common-law trademark is recognized.
-
-OSI CERTIFICATION:
-
-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
-a certification mark of the Open Source Initiative. OSI has not addressed
-the additional disclaimers inserted at version 1.0.7.
-
-EXPORT CONTROL:
-
-The Copyright owner believes that the Export Control Classification
-Number (ECCN) for libpng is EAR99, which means not subject to export
-controls or International Traffic in Arms Regulations (ITAR) because
-it is open source, publicly available software, that does not contain
-any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
-734.7(b).
-
-A "png_get_copyright" function is available, for convenient use in "about"
-boxes and the like:
-
-   printf("%s", png_get_copyright(NULL));
-
-Also, the PNG logo (in PNG format, of course) is supplied in the
-files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
-
-Glenn Randers-Pehrson
-July 15, 2018
-
 .\" end of man page
diff --git a/libpngpf.3 b/libpngpf.3
index ed371a4..cd8a942 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,7 +1,8 @@
-.TH LIBPNGPF 3 "July 15, 2018"
+.TH LIBPNGPF 3 "2018-Jul-29"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.35
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.36.git
 (private functions)
+
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
 
@@ -16,7 +17,8 @@
 available for use by applications.  They are not "exported" to applications
 using shared libraries.
 
-.SH SEE ALSO
+.SH "SEE ALSO"
 .BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
-.SH AUTHOR
-Glenn Randers-Pehrson
+
+.SH AUTHORS
+Cosmin Truta, Glenn Randers-Pehrson
diff --git a/png.5 b/png.5
index b0cbd2c..b5bba26 100644
--- a/png.5
+++ b/png.5
@@ -1,47 +1,49 @@
-.TH PNG 5 "April 1, 2017"
+.TH PNG 5 "2018-Jul-29"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
+
 .SH DESCRIPTION
 PNG (Portable Network Graphics) is an extensible file format for the
-lossless, portable, well-compressed storage of raster images. PNG provides
-a patent-free replacement for GIF and can also replace many
+lossless, portable, well-compressed storage of raster images.  PNG
+provides a patent-free replacement for GIF, and can also replace many
 common uses of TIFF. Indexed-color, grayscale, and truecolor images are
-supported, plus an optional alpha channel. Sample depths range from
+supported, plus an optional alpha channel.  Sample depths range from
 1 to 16 bits.
 .br
-
-PNG is designed to work well in online viewing applications, such as the
-World Wide Web, so it is fully streamable with a progressive display
-option. PNG is robust, providing both full file integrity checking and
-fast, simple detection of common transmission errors. Also, PNG can store
-gamma and chromaticity data for improved color matching on heterogeneous
-platforms.
+PNG is designed to work well in online viewing applications, such
+as the World Wide Web, so it is fully streamable with a progressive
+display option.  PNG is robust, providing both full file integrity
+checking and fast, simple detection of common transmission errors.
+Also, PNG can store gamma and chromaticity data for improved color
+matching on heterogeneous platforms.
 
 .SH "SEE ALSO"
 .BR "libpng"(3), " libpngpf"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
 .LP
-PNG specification (second edition), November 2003:
+PNG Specification (Second Edition), November 2003:
 .IP
 .br
-  <https://www.w3.org/TR/2003/REC-PNG-20031110/
-PNG 1.2 specification, July 1999:
+https://www.w3.org/TR/2003/REC-PNG-20031110/
+.LP
+PNG 1.2 Specification, July 1999:
 .IP
 .br
 https://png-mng.sourceforge.io/pub/png/spec/1.2/
 .LP
-PNG 1.0 specification, October 1996:
+PNG 1.0 Specification, October 1996:
 .IP
 .br
 RFC 2083
-.IP
 .br
 https://www.ietf.org/rfc/rfc2083.txt
+.IP
 .br
-or (as a W3C Recommendation) at
+or W3C Recommendation
 .br
 https://www.w3.org/TR/REC-png-961001
+
 .SH AUTHORS
-This man page: Glenn Randers-Pehrson
+This man page: Cosmin Truta, Glenn Randers-Pehrson
 .LP
 Portable Network Graphics (PNG) Specification (Second Edition)
 Information technology - Computer graphics and image processing -
@@ -53,22 +55,30 @@
 .LP
 Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
 Thomas Boutell and others (png-list).
-.LP
 
-
-.SH COPYRIGHT NOTICE
+.SH COPYRIGHT
 .LP
-This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson.  See png.h
-for conditions of use and distribution.
+This man page is
+.br
+Copyright (c) 2018 Cosmin Truta.
+.br
+Copyright (c) 1998-2006 Glenn Randers-Pehrson.
+.br
+See png.h for conditions of use and distribution.
 .LP
 The PNG Specification (Second Edition) is
+.br
 Copyright (c) 2003 W3C. (MIT, ERCIM, Keio), All Rights Reserved.
 .LP
-The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
+The PNG-1.2 Specification is
+.br
+Copyright (c) 1999 Glenn Randers-Pehrson.
+.br
 See the specification for conditions of use and distribution.
 .LP
-The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute of
-Technology.  See the specification for conditions of use and distribution.
-.LP
+The PNG-1.0 Specification is
+.br
+Copyright (c) 1996 Massachusetts Institute of Technology.
+.br
+See the specification for conditions of use and distribution.
 .\" end of man page
-
diff --git a/png.h b/png.h
index 1e1b45e..ab3424a 100644
--- a/png.h
+++ b/png.h
@@ -221,15 +221,15 @@
  *    ...
  *    1.6.35                  16    10635  16.so.16.35[.0]
  *
- *    Henceforth the source version will match the shared-library major
- *    and minor numbers; the shared-library major version number will be
- *    used for changes in backward compatibility, as it is intended.  The
- *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
- *    for applications, is an unsigned integer of the form xyyzz corresponding
- *    to the source version x.y.z (leading zeros in y and z).  Beta versions
- *    were given the previous public release number plus a letter, until
- *    version 1.0.6j; from then on they were given the upcoming public
- *    release number plus "betaNN" or "rcNN".
+ *    Henceforth the source version will match the shared-library major and
+ *    minor numbers; the shared-library major version number will be used for
+ *    changes in backward compatibility, as it is intended.
+ *    The PNG_LIBPNG_VER macro, which is not used within libpng but is
+ *    available for applications, is an unsigned integer of the form XYYZZ
+ *    corresponding to the source version X.Y.Z (leading zeros in Y and Z).
+ *    Beta versions were given the previous public release number plus a
+ *    letter, until version 1.0.6j; from then on they were given the upcoming
+ *    public release number plus "betaNN" or "rcNN".
  *
  *    Binary incompatibility exists only when applications make direct access
  *    to the info_ptr or png_ptr members through png.h, and the compiled
@@ -240,7 +240,7 @@
  *
  * See libpng.txt or libpng.3 for more information.  The PNG specification
  * is available as a W3C Recommendation and as an ISO Specification,
- * <https://www.w3.org/TR/2003/REC-PNG-20031110/
+ * <https://www.w3.org/TR/2003/REC-PNG-20031110/>
  */
 
 #ifndef PNG_H
@@ -292,11 +292,12 @@
 
 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
 
-/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
- * We must not include leading zeros.
- * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
- * version 1.0.0 was mis-numbered 100 instead of 10000).  From
- * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
+/* Careful here.  At one time, Guy wanted to use 082, but that
+ * would be octal.  We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
+ * (only version 1.0.0 was mis-numbered 100 instead of 10000).
+ * From version 1.0.1 it is:
+ * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
 #define PNG_LIBPNG_VER 10636 /* 1.6.36 */
 
@@ -2713,7 +2714,7 @@
  *
  * When the simplified API needs to convert between sRGB and linear colorspaces,
  * the actual sRGB transfer curve defined in the sRGB specification (see the
- * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+ * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
  * approximation used elsewhere in libpng.
  *
  * When an alpha channel is present it is expected to denote pixel coverage
diff --git a/scripts/README.txt b/scripts/README.txt
index e217713..e7bb6f7 100644
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,11 +1,11 @@
 
 Makefiles for libpng
 
-pnglibconf.h.prebuilt       =>  Stores configuration settings
+pnglibconf.h.prebuilt  =>  Configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.*)
+                       (gcc, creates shared libpng16.so.16.1.6.*)
  makefile.linux-opt=>  Linux/ELF makefile with hardware optimizations on
-                       (gcc, creates libpng16.so.16.1.6.*)
+                       (gcc, creates shared libpng16.so.16.1.6.*)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -15,10 +15,10 @@
  makefile.amiga    =>  Amiga makefile
  makefile.atari    =>  Atari makefile
  makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
- makefile.beos     =>  beos makefile
+ makefile.beos     =>  BeOS makefile
  makefile.bor      =>  Borland makefile (uses bcc)
  makefile.cegcc    =>  minge32ce for Windows CE makefile
- makefile.darwin   =>  Darwin makefile, can use on MacosX
+ makefile.darwin   =>  Darwin makefile, for macOS (formerly Mac OS X)
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.freebsd  =>  FreeBSD makefile
@@ -30,17 +30,17 @@
  makefile.intel    =>  Intel C/C++ version 4.0 and later
  makefile.mips     =>  MIPS makefile
  makefile.msc      =>  Microsoft C makefile
- makefile.netbsd   =>  NetBSD/cc makefile, makes libpng.so.
+ makefile.netbsd   =>  NetBSD/cc makefile, makes shared libpng.so
  makefile.openbsd  =>  OpenBSD makefile
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
- makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+ makefile.sco      =>  SCO OSr5 ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics makefile
-                       (gcc, creates libpng16.so.16.1.6.*)
+                       (gcc, creates shared libpng16.so.16.1.6.*)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile
-                       (gcc, creates libpng16.so.16.1.6.*)
+                       (gcc, creates shared libpng16.so.16.1.6.*)
  makefile.so9      =>  Solaris 9 makefile
-                       (gcc, creates libpng16.so.16.1.6.*)
+                       (gcc, creates shared libpng16.so.16.1.6.*)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
@@ -57,20 +57,20 @@
  libpng-config-body.in => used by several makefiles to create libpng-config
  libpng-config-head.in => used by several makefiles to create libpng-config
  libpng.pc.in      =>  Used by several makefiles to create libpng.pc
- pngwin.rc         =>  Used by the visualc71 project.
+ pngwin.rc         =>  Used by the visualc71 project
  pngwin.def        =>  Used by makefile.os2
  pngwin.dfn        =>  Used to maintain pngwin.def
  SCOPTIONS.ppc     =>  Used with smakefile.ppc
 
- checksym.awk       =>  Used for maintaining pnglibconf.h
- def.dfn            =>  Used for maintaining pnglibconf.h
- options.awk        =>  Used for maintaining pnglibconf.h
- pnglibconf.dfa     =>  Used for maintaining pnglibconf.h
- pnglibconf.mak     =>  Used for maintaining pnglibconf.h
- sym.dfn            =>  Used for symbol versioning
- symbols.def        =>  Used for symbol versioning
- symbols.dfn        =>  Used for symbol versioning
- vers.dfn           =>  Used for symbol versioning
+ checksym.awk      =>  Used for maintaining pnglibconf.h
+ def.dfn           =>  Used for maintaining pnglibconf.h
+ options.awk       =>  Used for maintaining pnglibconf.h
+ pnglibconf.dfa    =>  Used for maintaining pnglibconf.h
+ pnglibconf.mak    =>  Used for maintaining pnglibconf.h
+ sym.dfn           =>  Used for symbol versioning
+ symbols.def       =>  Used for symbol versioning
+ symbols.dfn       =>  Used for symbol versioning
+ vers.dfn          =>  Used for symbol versioning
 
  libtool.m4        =>  Used by autoconf tools
  ltoptions.m4      =>  Used by autoconf tools