= libpng =

== Description ==

libpng is the official PNG reference library. It supports almost all PNG features, is extensible, and has been extensively tested for over 13 years. The home site for development versions (i.e., may be buggy or subject to change or include experimental features) is http://libpng.sourceforge.net/, and the place to go for questions about the library is the png-mng-implement mailing list.

Website: http://www.libpng.org/pub/png/libpng.html

== License ==

The libpng license - see http://www.libpng.org/pub/png/src/libpng-LICENSE.txt

== SPKG Maintainers ==

 * Michael Abshoff
 * William Stein

== Upstream Contact ==

The png mailing lists - see http://www.libpng.org/pub/png/pngmisc.html#lists

== Dependencies ==

This spkg requires 

 * libz

This spkg provides dependencies for

 * the Sage library
 * tachyon
 * matplotlib

== Special Update/Build Instructions ==

 * No changes went into src. There are two different tarballs, but we use the one with configure.

== Changelog ==

=== libpng-1.2.35 (Michael Abshoff, April 10th, 2009) ===
 * update to latest upstream due to security issue in libpng (#5696)
 
=== libpng-1.2.34 (Michael Abshoff, February 15th, 2009) ===
 * update to latest upstream release (security related)
 * delete SAGE_LOCAL/lib/libpng.* to avoid OSX specific issues. This required a set of other fixes.
 * unset RM
 * check if SAGE_LOCAL is set

=== libpng-1.2.22.p8 (Michael Abshoff, August 29th, 2008) ===
 * Do not delete libpng.dylib on OSX

=== libpng-1.2.22.p7 (Michael Abshoff, May 22nd, 2008) ===
 * on OSX: delete libtool files also to make graphviz compile on OSX

=== libpng-1.2.22.p6 (Michael Abshoff, May 18th, 2008) ===
 * improve 64 bit OSX build support

=== libpng-1.2.22.p5 (michael Abshoff, Feb. 15th, 2008) ===
 * add OSX 10.5 64 bit support
 * fix zlib headers detection issue (#2068)

=== libpng-1.2.22.p4 (Michael Abshoff, Jan. 31st, 2008) ===
 * remove loads of ._* files (#2010)