depends libxml2 &&

optional_depends perl --with-perl-binding --without-perl-binding "for perl bindings" &&
optional_depends python --with-python-binding --without-python-binding "for python bindings" &&
optional_depends -sub CXX gcc --with-cxx-binding --without-cxx-binding "for c++ bindings and demo" &&
optional_depends tcl --with-tcl=/usr/lib  "for tcl bindings and demo" &&
optional_depends gd --with-rigmatrix --without-rigmatrix "for the rigmatrix tool"