Libpng

libpng is the official Portable Network Graphics (PNG) reference library (originally called pnglib). It is a platform-independent library that contains C functions for handling PNG images. It supports almost all of PNG's features, is extensible, and has been widely used and tested for over 28 years.^[2] libpng is dependent on zlib for data compression and decompression routines.

libpng is released under the libpng license, a permissive free software licence, and is free software. It is frequently used in both free and proprietary software, either directly or through the use of a higher level image library.

As of 2017^[update] the latest versions in the 1.6.x and 1.5.x branches were considered as release versions, while 1.4.x, 1.2.x, and 1.0.x were considered as legacy versions getting only security fixes.^[3] All vulnerability warnings and crash bugs are published on the main page.^[2]