As a sysadmin at a secondary school I've supported ms win os', novells' netware, apples osx, and several GNU based systems. I don't try to push anything, for the time being. Currently our school run our systems as we like, but there will be some standars enforced from central IT departments. Those will only support ms os' at server and desktop.

none, it was just a guess.

I run opera unite on a non-administrator account on ms winxp sp3, seems to work. I guess running opera unite with administrative rights on windows, would be dangerous.