I'm not someone that can be impressed easily... However, after going through the forums on this site and on RunUO, I must say that the XMLSpawner is the best concept / script / tool available for Ultima Online.
It is so versatile and configurable that you can practically do anything you wish.
A hearty congratulations and sincere thanks to all those who have taken part in its development.
Much of the enjoyment in working with UO comes from the ability to incorporate new and creative play elements and much of the development of xmlspawner and the related systems has relied on ideas from users, so suggestions for new and fun things to do are always welcome.
Play on!