I'm going to try out the folders branch today. I just skimmed the CVS through the web interface, and there are no recent folder-specific updates in the db_support directory. Does this version use the exact same db tables as the main branch? Could I even replace an existing Antville installation with the folders version, on top of an existing db?

need just one new column in AV_TEXT (TEXT_ALIAS), there's no need to create a new db just for the folders branch. if you already have that then your db is ready for the folders branch. otherwise have a look at antville_dbpatch20030303.sql in CVS, there you can find the 'add column' statement.