diff --git a/ANNOUNCE b/ANNOUNCE
index 2cc05ca..94a9f45 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.30beta01 - March 30, 2017
+Libpng 1.6.30beta01 - April 1, 2017
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -25,11 +25,12 @@
 
 Changes since the last public release (1.6.29):
 
-Version 1.6.30beta01 [March 30, 2017]
+Version 1.6.30beta01 [April 1, 2017]
   Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
     makefile.linux and makefile.solaris-x86 (Cosmin).
   Revised documentation of png_get_error_ptr() in the libpng manual.
-  Silence clang -Wcomma and const drop warnings (Viktor SzaKats).
+  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
+  Update Sourceforge URLs in documentation (https instead of http).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 9cede4e..93722ed 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5818,11 +5818,12 @@
 Version 1.6.29 [March 16, 2017]
   No changes.
 
-Version 1.6.30beta01 [March 30, 2017]
+Version 1.6.30beta01 [April 1, 2017]
   Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
     makefile.linux and makefile.solaris-x86 (Cosmin).
   Revised documentation of png_get_error_ptr() in the libpng manual.
-  Silence clang -Wcomma and const drop warnings (Viktor SzaKats).
+  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
+  Update Sourceforge URLs in documentation (https instead of http).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/LICENSE b/LICENSE
index e5d9ccf..99818ad 100644
--- a/LICENSE
+++ b/LICENSE
@@ -10,7 +10,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, March 16, 2017 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, April 1, 2017 are
 Copyright (c) 2000-2002, 2004, 2006-2017 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
@@ -130,4 +130,4 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 16, 2017
+April 1, 2017
diff --git a/README b/README
index 418eb1e..c15d91f 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.30beta01 - March 16, 2017 (shared library 16.0)
+README for libpng version 1.6.30beta01 - April 1, 2017 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 7d6d0c8..7a3a972 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.30beta01 - March 28, 2017
+ libpng version 1.6.30beta01 - April 1, 2017
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.30beta01 - March 28, 2017
+ libpng versions 0.97, January 1998, through 1.6.30beta01 - April 1, 2017
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
@@ -66,17 +66,17 @@
 
 The PNG specification (second edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
-<https://www.w3.org/TR/2003/REC-PNG-20031110/
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
 The W3C and ISO documents have identical technical content.
 
 The PNG-1.2 specification is available at
-<https://png-mng.sourceforge.io/pub/png/spec/1.2/>.
+<http://png-mng.sourceforge.net/pub/png/spec/1.2/>.
 It is technically equivalent
 to the PNG specification (second edition) but has some additional material.
 
-The PNG-1.0 specification is available as RFC 2083
-<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
-W3C Recommendation <https://www.w3.org/TR/REC-png-961001>.
+The PNG-1.0 specification is available as RFC 2083 
+<http://png-mng.sourceforge.net/pub/png/spec/1.0/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC-png-961001>.
 
 Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/spec/register/>
@@ -3824,7 +3824,7 @@
 
 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 http://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
@@ -4088,7 +4088,7 @@
 
 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 http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
 approximation used elsewhere in libpng.
 
 WRITE APIS
@@ -4269,7 +4269,7 @@
 after a longjmp, so the user may want to be careful about doing anything
 after setjmp returns non-zero besides returning itself.  Consult your
 compiler documentation for more details.  For an alternative approach, you
-may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/),
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
 Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
@@ -4497,7 +4497,7 @@
 and the MHDR and MEND chunks.  Libpng does not provide support for these
 or any other MNG chunks; your application must provide its own support for
 them.  You may wish to consider using libmng (available at
-https://www.libmng.com/) instead.
+http://www.libmng.com) instead.
 
 VIII.  Changes to Libpng from version 0.88
 
@@ -5197,7 +5197,7 @@
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    https://git.code.sf.net/p/libpng/code.git
+    git://git.code.sf.net/p/libpng/code
 
 or you can browse it with a web browser by selecting the "code" button at
 
@@ -5207,7 +5207,7 @@
 png-mng-implement at lists.sourceforge.net or you can upload them to
 the libpng bug tracker at
 
-    https://libpng.sourceforge.io/
+    http://libpng.sourceforge.net
 
 We also accept patches built from the tar or zip distributions, and
 simple verbal discriptions of bug fixes, reported either to the
@@ -5217,7 +5217,7 @@
 XV. Coding style
 
 Our coding style is similar to the "Allman" style
-(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
+(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5318,7 +5318,7 @@
 though it were a function.
 
 Control keywords if, for, while, and switch are always followed by a space
-to distinguish them from function calls, which have no trailing space.
+to distinguish them from function calls, which have no trailing space. 
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5344,7 +5344,7 @@
 
 We prefer "if (something != 0)" and "if (something == 0)" over
 "if (something)" and if "(!something)", respectively, and for pointers
-we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)".
+we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)". 
 
 We do not use the TAB character for indentation in the C sources.
 
diff --git a/libpng.3 b/libpng.3
index d9e66d8..3b65129 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "March 28, 2017"
+.TH LIBPNG 3 "April 1, 2017"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.6.30beta01
 .SH SYNOPSIS
@@ -510,7 +510,7 @@
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.30beta01 - March 28, 2017
+ libpng version 1.6.30beta01 - April 1, 2017
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
@@ -521,7 +521,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.30beta01 - March 28, 2017
+ libpng versions 0.97, January 1998, through 1.6.30beta01 - April 1, 2017
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
@@ -576,17 +576,17 @@
 
 The PNG specification (second edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
-<https://www.w3.org/TR/2003/REC-PNG-20031110/
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
 The W3C and ISO documents have identical technical content.
 
 The PNG-1.2 specification is available at
-<https://png-mng.sourceforge.io/pub/png/spec/1.2/>.
+<http://png-mng.sourceforge.net/pub/png/spec/1.2/>.
 It is technically equivalent
 to the PNG specification (second edition) but has some additional material.
 
-The PNG-1.0 specification is available as RFC 2083
-<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
-W3C Recommendation <https://www.w3.org/TR/REC-png-961001>.
+The PNG-1.0 specification is available as RFC 2083 
+<http://png-mng.sourceforge.net/pub/png/spec/1.0/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC-png-961001>.
 
 Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/spec/register/>
@@ -4334,7 +4334,7 @@
 
 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 http://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
@@ -4598,7 +4598,7 @@
 
 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 http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
 approximation used elsewhere in libpng.
 
 WRITE APIS
@@ -4779,7 +4779,7 @@
 after a longjmp, so the user may want to be careful about doing anything
 after setjmp returns non-zero besides returning itself.  Consult your
 compiler documentation for more details.  For an alternative approach, you
-may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/),
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
 Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
@@ -5007,7 +5007,7 @@
 and the MHDR and MEND chunks.  Libpng does not provide support for these
 or any other MNG chunks; your application must provide its own support for
 them.  You may wish to consider using libmng (available at
-https://www.libmng.com/) instead.
+http://www.libmng.com) instead.
 
 .SH VIII.  Changes to Libpng from version 0.88
 
@@ -5707,7 +5707,7 @@
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    https://git.code.sf.net/p/libpng/code.git
+    git://git.code.sf.net/p/libpng/code
 
 or you can browse it with a web browser by selecting the "code" button at
 
@@ -5717,7 +5717,7 @@
 png-mng-implement at lists.sourceforge.net or you can upload them to
 the libpng bug tracker at
 
-    https://libpng.sourceforge.io/
+    http://libpng.sourceforge.net
 
 We also accept patches built from the tar or zip distributions, and
 simple verbal discriptions of bug fixes, reported either to the
@@ -5727,7 +5727,7 @@
 .SH XV. Coding style
 
 Our coding style is similar to the "Allman" style
-(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
+(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5828,7 +5828,7 @@
 though it were a function.
 
 Control keywords if, for, while, and switch are always followed by a space
-to distinguish them from function calls, which have no trailing space.
+to distinguish them from function calls, which have no trailing space. 
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5854,7 +5854,7 @@
 
 We prefer "if (something != 0)" and "if (something == 0)" over
 "if (something)" and if "(!something)", respectively, and for pointers
-we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)".
+we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)". 
 
 We do not use the TAB character for indentation in the C sources.
 
@@ -5987,7 +5987,7 @@
 .LP
 .IR libpng :
 .IP
-https://libpng.sourceforge.io/ (follow the [DOWNLOAD] link)
+http://libpng.sourceforge.net (follow the [DOWNLOAD] link)
 http://www.libpng.org/pub/png
 
 .LP
@@ -5997,7 +5997,7 @@
 .I libpng
 or at
 .br
-http://zlib.net/
+ftp://ftp.info-zip.org/pub/infozip/zlib
 
 .LP
 .IR PNG specification: RFC 2083
@@ -6006,11 +6006,11 @@
 .I libpng
 or at
 .br
-https://www.ietf.org/rfc/rfc2083.txt
+ftp://ftp.rfc-editor.org:/in-notes/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
-https://www.w3.org/TR/REC-png.html
+http://www.w3.org/TR/REC-png.html
 
 .LP
 In the case of any inconsistency between the PNG specification
@@ -6026,7 +6026,7 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.30beta01 - March 28, 2017:
+Libpng version 1.6.30beta01 - April 1, 2017:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6051,7 +6051,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, March 28, 2017 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, April 1, 2017 are
 Copyright (c) 2000-2002, 2004, 2006-2017 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
@@ -6179,7 +6179,7 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 28, 2017
+April 1, 2017
 
 .\" end of man page
 
diff --git a/libpngpf.3 b/libpngpf.3
index 4b4c742..7e6d4a4 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,4 +1,4 @@
-.TH LIBPNGPF 3 "March 16, 2017"
+.TH LIBPNGPF 3 "April 1, 2017"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.6.30beta01
 (private functions)
diff --git a/png.5 b/png.5
index 15819de..b0cbd2c 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "March 16, 2017"
+.TH PNG 5 "April 1, 2017"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index c533dfd..266e42c 100644
--- a/png.c
+++ b/png.c
@@ -776,14 +776,14 @@
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.30beta01 - March 30, 2017" PNG_STRING_NEWLINE \
+      "libpng version 1.6.30beta01 - April 1, 2017" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
       "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
       "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
       PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.30beta01 - March 30, 2017\
+   return "libpng version 1.6.30beta01 - April 1, 2017\
       Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
diff --git a/png.h b/png.h
index 3cea6b6..abbb024 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.30beta01, March 30, 2017
+ * libpng version 1.6.30beta01, April 1, 2017
  *
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.30beta01, March 30, 2017:
+ *   libpng versions 0.97, January 1998, through 1.6.30beta01, April 1, 2017:
  *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
  */
@@ -25,7 +25,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, March 30, 2017 are
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.30beta01, April 1, 2017 are
  * Copyright (c) 2000-2002, 2004, 2006-2017 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
@@ -241,7 +241,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 30, 2017
+ *    April 1, 2017
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -310,7 +310,7 @@
 
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.30beta01"
-#define PNG_HEADER_VERSION_STRING " libpng version 1.6.30beta01 - March 30, 2017\n"
+#define PNG_HEADER_VERSION_STRING " libpng version 1.6.30beta01 - April 1, 2017\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
diff --git a/pngconf.h b/pngconf.h
index 79c8ef7..690a319 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.30beta01, March 30, 2017
+ * libpng version 1.6.30beta01, April 1, 2017
  *
  * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/projects/vstudio/README.txt b/projects/vstudio/README.txt
index 4eef9c7..3b26b76 100644
--- a/projects/vstudio/README.txt
+++ b/projects/vstudio/README.txt
@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.30beta01 - March 16, 2017
+libpng version 1.6.30beta01 - April 1, 2017
 
 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
 
diff --git a/projects/vstudio/zlib.props b/projects/vstudio/zlib.props
index 4d69efa..7233223 100644
--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.30beta01 - March 16, 2017
+ * libpng version 1.6.30beta01 - April 1, 2017
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
diff --git a/scripts/README.txt b/scripts/README.txt
index e05c20c..0bec2e4 100644
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,5 +1,5 @@
 
-Makefiles for  libpng version 1.6.30beta01 - March 16, 2017
+Makefiles for  libpng version 1.6.30beta01 - April 1, 2017
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index e844b85..7e26e1e 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -2,7 +2,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.30beta01 - March 16, 2017 */
+/* Libpng version 1.6.30beta01 - April 1, 2017 */
 
 /* Copyright (c) 1998-2015 Glenn Randers-Pehrson */