optional_depends %JPEG  "--enable-jpeg"  "--enable-jpeg=local" "If yes, use system jpeg"
optional_depends zlib   "--enable-zlib"  "--enable-zlib=local" "If yes use system zlib"
optional_depends libpng "--enable-png"   "--enable-png=local"  "If yes use system libpng"
optional_depends cairo  "--enable-cairo" "--disable-cairo"     "For cairo graphics support, Do not enable for dillo"

