A new era for content management on this site: I switched from Mambo to Joomla, the new open-managed fork of the old CMS of choice. (I like the open-managed moniker.)
The transition was neither hard nor easy. I decided to try the copy instructions: copy the site to a new location, copy Joomla on top of it, then deal with all the problems.
Mostly, I had to retrieve files I had changed (like sef.php or the custom image on top). A little extra time went into debugging: I had to change the configuration to go to a different directory, and then revert back.