[Libvir] Newbie questions!

Hello! I`m trying o use libvirt (or libvir?) what`s the difference? (this is the first question!) So, I compiled libvirt and libvir on my ia64 system(debian sarge 3.1) and download the code exemple of the website http://libvirt.org named info1.c To compile I used: "gcc -o test_dom0 test_dom0.c -lvirt" and ok. But when I try to run, shows the error below: peso@debian-ia64:~/test_libvirt$ ./test_dom0 libvir: error : no support for hypervisor Xen Failed to connect to hypervisor I tryied too to compile using: "gcc -o test_dom0 test_dom0.c -lvir" but doesn`t work too: peso@debian-ia64:~/test_libvirt$ ./test_dom0 Failed to find Domain 0 Thanks!