libpng
on SourceForge
libpng15/older-releases/1.5.28/lpng1528.zip.asc
libpng15/older-releases/1.5.28/lpng1528.7z.asc
libpng15/older-releases/1.5.28/libpng-1.5.28.tar.xz.asc
libpng15/older-releases/1.5.28/libpng-1.5.28.tar.gz.asc
libpng12/older-releases/1.2.57/lpng1257.zip.asc
libpng12/older-releases/1.2.57/lpng1257.7z.asc
libpng12/older-releases/1.2.57/libpng-1.2.57.tar.xz.asc