- libcurl: http://libcurl.org/
- libjpeg: http://www.ijg.org/
- libopenjpeg: http://www.openjpeg.org/
- libtiff: http://zh.wikipedia.org/zh/LibTIFF , http://www.remotesensing.org/libtiff
- libpng: http://www.libpng.org/
- zlib: http://www.zlib.net/
- cairo: http://cairographics.org/
- glibc: http://www.gnu.org/software/libc/