For what its worth, I also use UO Steam, as well as EasyUO, and OpenEasyUO.
They are all portable, in that you can install them all under the same directory structure, and then zip up the entire directory structure to copy them to a thumbdrive for a backup in case an update breaks something, or in case you want to copy everything to another PC. Just throw a copy of that pesky Microsoft dependency in the folder to install if you are going to run it from a new computer.
Cartographer is slightly trickier, but it lives in the same folder as well. The trick is that it has some files that need copied into the user profile the first time it is run on a new machine.
My UO folder lives on my desktop, with subfolders for the game itself, and each scripting engine. I never update anything without creating a zip file of the entire mess first, and I have never broken it and not been able to easily recover.
