The next project on my Mac is to install Jaguar on it. I'm planning to install it on a separate partition so that I can keep 10.1.5 in working order too, but if updates should suddenly stop here, it's probably because my main Mac is caught in upgrade hell. With OS 9.x and prior, I never felt apprehensive about upgrading. Undoing it, or getting out of any problems was easy. Now, with OS X, I feel a slight twinge of trepidation as I set out on the upgrade path. I think I'll be back though.