Nothing free comes to mind, but I could put in a plug for FMS's Total Access Analyzer. I've used it extensively to document a bunch of complex db's and have always been really happy with it. It installs as an add-in with menu access. Ain't nothin' it doesn't document (completely "printablely"), including code modules (both VBA and user-defined functions and subs, arguments, parameters, the whole nine). Addresses performance issues too. Worth having around.