libpng
on SourceForge
libpng16/older-releases/1.6.21beta/libpng-1.6.21beta01.tar.gz
libpng15/older-releases/1.5.26beta/libpng-1.5.26beta01.tar.gz
libpng14/older-releases/1.4.19beta/libpng-1.4.19beta01.tar.gz
libpng12/older-releases/1.2.56beta/libpng-1.2.56beta01.tar.gz