optional_depends gd     "--with-gd"  "--without-gd"  "for additional graphics support"
optional_depends libpng "--with-png" "--without-png" "enable png terminal"
optional_depends "%X"   "--with-x"   "--without-x"   "Use X window system"
optional_depends lua    "--with-lua" "--without-lua" "For Lua scripting support"
optional_depends libggi "--with-ggi" "--without-ggi" "For General Graphics Interface support"

optional_depends texlive     "--with-latex"        "--without-latex"         "for latex support"
optional_depends PDFlib-Lite "--with-pdf"          "--without-pdf"           "for PDF file support"
optional_depends readline    "--with-readline=gnu" "--with-readline=builtin" "For system or builtin readline support, 'y' for system"

