PNG Reference Library: libpng
This is an open source project to develop and maintain the reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files.
The primary web site for PNG is www.libpng.org/pub/png.
The primary public ftp site for libpng is ftp://ftp.simplesystems.org/pub/png.
The ftp site for beta versions of libpng is ftp://ftp.simplesystems.org/pub/png-group/.
The current public and beta versions of libpng are available at https://sourceforge.net/project/showfiles.php?group_id=5624.
UPDATE 28 July 2015: The current public releases can also be downloaded directly from github, by using "wget" as illustrated below, or by selecting the link in your browser:
There are pointers to various distributions of libpng and MD5 checksums here.
The Sourceforge project page for libpng is at https://sourceforge.net/projects/libpng/
A "git" repository for libpng is available. You can access it by cloning git://git.code.sf.net/p/libpng/code or you can browse it at github.com/glennrp/libpng. or at sourceforge.net/p/libpng/code. At present, there are eight branches (libpng00, libpng10, libpng12, libpng14, libpng15, libpng16, libpng17, and a "master" branch which is roughly equivalent to the "libpng16" branch). Development occurs in the "libpng16" and "libpng17" branches; parts of the new developments are also ported to the "libpng15" branch; the rest are just for legacy and security purposes.
A "doxygen" index for various releases is available at fossies.org/libpng.
A "compatibility analysis" of libpng releases through 1.6.18beta09 is available at upstream.org (service discontinued July 21, 2015).
The Coverity project for libpng is at https://scan.coverity.com/projects/4061. The project is set up to scan the head of each of the libpng10 through libpng17 branches (libpng00 is not included). As of July 23, 2015, libpng-1.0.63, libpng-1.2.53, libpng-1.4.16beta02, libpng-1.5.23, libpng-1.6.18, and libpng-1.7.0beta63 were all reported to be defect-free).
The mailing list for libpng developers and developers of libpng-based applications is png-mng-implement (at) lists.sourceforge.net. Visit http://png-mng.sourceforge.net/pub/png/pngmisc.html#lists to subscribe. (archived here)
Bug reports can be sent to the mailing list or submitted via the SourceForge Bug tracker (select the "Create Ticket" button).
Feel free to download and use the official PNG logo (size 88x31) with your application documentation and web pages:
This site belongs to the PNG Development Group and is maintained for the group by Glenn Randers-Pehrson glennrp at users.sourceforge.net
Web space for this project is being provided by sourceforge.net