Running an application with root privileges at Linux

Is there any standard way (that applies to all Linux distributions), a
GUI application (X.Org/Gnome/KDE) to ask for the root password so as to
execute with root privileges?


Software examples that do this:

Synaptic at Ubuntu.

Yumex at Fedora.


I am writing a free and open source program
(http://www.cpp-software.net/software.html), and I call Ubuntu's
"gksudo" from within the program, but I prefer a portable way, that
applies to all Linux with X.Org distributions.


Thanks.